cellfun.cc

Go to the documentation of this file.

/*

Copyright (C) 2005-2018 Mohamed Kamoun
Copyright (C) 2006-2018 Bill Denney
Copyright (C) 2009 Jaroslav Hajek
Copyright (C) 2010 VZLU Prague

This file is part of Octave.

Octave is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Octave is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Octave; see the file COPYING.  If not, see
<https://www.gnu.org/licenses/>.

*/

#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include <string>
#include <vector>
#include <list>
#include <memory>

#include "lo-mappers.h"
#include "oct-locbuf.h"
#include "oct-string.h"

#include "Cell.h"
#include "oct-map.h"
#include "defun.h"
#include "interpreter.h"
#include "parse.h"
#include "variables.h"
#include "unwind-prot.h"
#include "errwarn.h"
#include "utils.h"

#include "ov-bool.h"
#include "ov-class.h"
#include "ov-colon.h"
#include "ov-complex.h"
#include "ov-float.h"
#include "ov-flt-complex.h"
#include "ov-int16.h"
#include "ov-int32.h"
#include "ov-int64.h"
#include "ov-int8.h"
#include "ov-scalar.h"
#include "ov-uint16.h"
#include "ov-uint32.h"
#include "ov-uint64.h"
#include "ov-uint8.h"

#include "ov-fcn-handle.h"

static octave_value_list
get_output_list (octave_idx_type count, octave_idx_type nargout,
                 const octave_value_list& inputlist,
                 octave_value& func,
                 octave_value& error_handler)
{
  octave_value_list tmp;

  bool execution_error = false;

  try
    {
      tmp = octave::feval (func, inputlist, nargout);
    }
  catch (const octave::execution_exception& e)
    {
      if (error_handler.is_defined ())
        {
          octave::interpreter::recover_from_exception ();

          execution_error = true;
        }
      else
        throw e;
    }

  if (execution_error)
    {
      if (error_handler.is_defined ())
        {
          octave_scalar_map msg;
          msg.assign ("identifier", last_error_id ());
          msg.assign ("message", last_error_message ());
          msg.assign ("index",
                      static_cast<double> (count
                                           + static_cast<octave_idx_type>(1)));

          octave_value_list errlist = inputlist;
          errlist.prepend (msg);

          buffer_error_messages--;

          tmp = octave::feval (error_handler, errlist, nargout);
        }
      else
        tmp.clear ();
    }

  return tmp;
}

// Templated function because the user can be stubborn enough to request
// a cell array as an output even in these cases where the output fits
// in an ordinary array
template <typename BNDA, typename NDA>
static octave_value_list
try_cellfun_internal_ops (const octave_value_list& args, int nargin)
{
  octave_value_list retval;

  std::string name = args(0).string_value ();

  const Cell f_args = args(1).cell_value ();

  octave_idx_type k = f_args.numel ();

  if (name == "isempty")
    {
      BNDA result (f_args.dims ());
      for (octave_idx_type count = 0; count < k; count++)
        result(count) = f_args.elem (count).isempty ();
      retval(0) = result;
    }
  else if (name == "islogical")
    {
      BNDA result (f_args.dims ());
      for (octave_idx_type count= 0; count < k; count++)
        result(count) = f_args.elem (count).islogical ();
      retval(0) = result;
    }
  else if (name == "isnumeric")
    {
      BNDA result (f_args.dims ());
      for (octave_idx_type count= 0; count < k; count++)
        result(count) = f_args.elem (count).isnumeric ();
      retval(0) = result;
    }
  else if (name == "isreal")
    {
      BNDA result (f_args.dims ());
      for (octave_idx_type count= 0; count < k; count++)
        result(count) = f_args.elem (count).isreal ();
      retval(0) = result;
    }
  else if (name == "length")
    {
      NDA result (f_args.dims ());
      for (octave_idx_type count= 0; count < k; count++)
        result(count) = static_cast<double> (f_args.elem (count).length ());
      retval(0) = result;
    }
  else if (name == "ndims")
    {
      NDA result (f_args.dims ());
      for (octave_idx_type count = 0; count < k; count++)
        result(count) = static_cast<double> (f_args.elem (count).ndims ());
      retval(0) = result;
    }
  else if (name == "numel" || name == "prodofsize")
    {
      NDA result (f_args.dims ());
      for (octave_idx_type count = 0; count < k; count++)
        result(count) = static_cast<double> (f_args.elem (count).numel ());
      retval(0) = result;
    }
  else if (name == "size")
    {
      if (nargin != 3)
        error (R"(cellfun: not enough arguments for "size")");

      int d = args(2).nint_value () - 1;

      if (d < 0)
        error ("cellfun: K must be a positive integer");

      NDA result (f_args.dims ());

      for (octave_idx_type count = 0; count < k; count++)
        {
          dim_vector dv = f_args.elem (count).dims ();
          if (d < dv.ndims ())
            result(count) = static_cast<double> (dv(d));
          else
            result(count) = 1.0;
        }

      retval(0) = result;
    }
  else if (name == "isclass")
    {
      if (nargin != 3)
        error (R"(cellfun: not enough arguments for "isclass")");

      std::string class_name = args(2).string_value ();
      BNDA result (f_args.dims ());
      for (octave_idx_type count = 0; count < k; count++)
        result(count) = (f_args.elem (count).class_name () == class_name);

      retval(0) = result;
    }

  return retval;
}

static void
get_mapper_fun_options (octave::symbol_table& symtab,
                        const octave_value_list& args,
                        int& nargin, bool& uniform_output,
                        octave_value& error_handler)
{
  while (nargin > 3 && args(nargin-2).is_string ())
    {
      std::string arg = args(nargin-2).string_value ();

      size_t compare_len = std::max (arg.length (), static_cast<size_t> (2));

      if (octave::string::strncmpi (arg, "uniformoutput", compare_len))
        uniform_output = args(nargin-1).bool_value ();
      else if (octave::string::strncmpi (arg, "errorhandler", compare_len))
        {
          if (args(nargin-1).is_function_handle ()
              || args(nargin-1).is_inline_function ())
            {
              error_handler = args(nargin-1);
            }
          else if (args(nargin-1).is_string ())
            {
              std::string err_name = args(nargin-1).string_value ();

              error_handler = symtab.find_function (err_name);

              if (error_handler.is_undefined ())
                error ("cellfun: invalid function NAME: %s",
                       err_name.c_str ());
            }
          else
            error ("cellfun: invalid value for 'ErrorHandler' function");
        }
      else
        error ("cellfun: unrecognized parameter %s", arg.c_str ());

      nargin -= 2;
    }

  nargin -= 1;
}

DEFMETHOD (cellfun, interp, args, nargout,
           doc: /* -*- texinfo -*-
@deftypefn  {} {} cellfun (@var{name}, @var{C})
@deftypefnx {} {} cellfun ("size", @var{C}, @var{k})
@deftypefnx {} {} cellfun ("isclass", @var{C}, @var{class})
@deftypefnx {} {} cellfun (@var{func}, @var{C})
@deftypefnx {} {} cellfun (@var{func}, @var{C}, @var{D})
@deftypefnx {} {[@var{a}, @dots{}] =} cellfun (@dots{})
@deftypefnx {} {} cellfun (@dots{}, "ErrorHandler", @var{errfunc})
@deftypefnx {} {} cellfun (@dots{}, "UniformOutput", @var{val})

Evaluate the function named @var{name} on the elements of the cell array
@var{C}.

Elements in @var{C} are passed on to the named function individually.  The
function @var{name} can be one of the functions

@table @code
@item isempty
Return 1 for empty elements.

@item islogical
Return 1 for logical elements.

@item isnumeric
Return 1 for numeric elements.

@item isreal
Return 1 for real elements.

@item length
Return a vector of the lengths of cell elements.

@item ndims
Return the number of dimensions of each element.

@item  numel
@itemx prodofsize
Return the number of elements contained within each cell element.  The
number is the product of the dimensions of the object at each cell element.

@item size
Return the size along the @var{k}-th dimension.

@item isclass
Return 1 for elements of @var{class}.
@end table

Additionally, @code{cellfun} accepts an arbitrary function @var{func}
in the form of an inline function, function handle, or the name of a
function (in a character string).  The function can take one or more
arguments, with the inputs arguments given by @var{C}, @var{D}, etc.
Equally the function can return one or more output arguments.  For example:

@example
@group
cellfun ("atan2", @{1, 0@}, @{0, 1@})
     @result{} [ 1.57080   0.00000 ]
@end group
@end example

The number of output arguments of @code{cellfun} matches the number of
output arguments of the function.  The outputs of the function will be
collected into the output arguments of @code{cellfun} like this:

@example
@group
function [a, b] = twoouts (x)
  a = x;
  b = x*x;
endfunction
[aa, bb] = cellfun (@@twoouts, @{1, 2, 3@})
     @result{}
        aa =
           1 2 3
        bb =
           1 4 9
@end group
@end example

Note that per default the output argument(s) are arrays of the same size as
the input arguments.  Input arguments that are singleton (1x1) cells will be
automatically expanded to the size of the other arguments.

If the parameter @qcode{"UniformOutput"} is set to true (the default),
then the function must return scalars which will be concatenated into the
return array(s).  If @qcode{"UniformOutput"} is false, the outputs are
concatenated into a cell array (or cell arrays).  For example:

@example
@group
cellfun ("tolower", @{"Foo", "Bar", "FooBar"@},
         "UniformOutput", false)
@result{} @{"foo", "bar", "foobar"@}
@end group
@end example

Given the parameter @qcode{"ErrorHandler"}, then @var{errfunc} defines a
function to call in case @var{func} generates an error.  The form of the
function is

@example
function [@dots{}] = errfunc (@var{s}, @dots{})
@end example

@noindent
where there is an additional input argument to @var{errfunc} relative to
@var{func}, given by @var{s}.  This is a structure with the elements
@qcode{"identifier"}, @qcode{"message"}, and @qcode{"index"} giving
respectively the error identifier, the error message, and the index into the
input arguments of the element that caused the error.  For example:

@example
@group
function y = foo (s, x), y = NaN; endfunction
cellfun ("factorial", @{-1,2@}, "ErrorHandler", @@foo)
@result{} [NaN 2]
@end group
@end example

Use @code{cellfun} intelligently.  The @code{cellfun} function is a
useful tool for avoiding loops.  It is often used with anonymous
function handles; however, calling an anonymous function involves an
overhead quite comparable to the overhead of an m-file function.
Passing a handle to a built-in function is faster, because the
interpreter is not involved in the internal loop.  For example:

@example
@group
a = @{@dots{}@}
v = cellfun (@@(x) det (x), a); # compute determinants
v = cellfun (@@det, a); # faster
@end group
@end example

@seealso{arrayfun, structfun, spfun}
@end deftypefn */)
{
  int nargin = args.length ();

  if (nargin < 2)
    print_usage ();

  if (! args(1).iscell ())
    error ("cellfun: C must be a cell array");

  octave_value_list retval;
  int nargout1 = (nargout < 1 ? 1 : nargout);

  octave_value func = args(0);

  octave::symbol_table& symtab = interp.get_symbol_table ();

  if (func.is_string ())
    {
      retval = try_cellfun_internal_ops<boolNDArray,NDArray> (args, nargin);

      if (! retval.empty ())
        return retval;

      // See if we can convert the string into a function.

      std::string name = args(0).string_value ();

      if (! valid_identifier (name))
        {
          std::string fcn_name = unique_symbol_name ("__cellfun_fcn__");
          std::string fname = "function y = " + fcn_name + "(x) y = ";

          octave_function *ptr_func
            = extract_function (args(0), "cellfun", fcn_name,
                                fname, "; endfunction");

          if (ptr_func)
            func = octave_value (ptr_func, true);
        }
      else
        {
          func = symtab.find_function (name);

          if (func.is_undefined ())
            error ("cellfun: invalid function NAME: %s", name.c_str ());
        }
    }

  if (! func.is_function_handle () && ! func.is_inline_function ()
      && ! func.is_function ())
    error ("cellfun: argument NAME must be a string or function handle");

  bool uniform_output = true;
  octave_value error_handler;

  get_mapper_fun_options (symtab, args, nargin, uniform_output, error_handler);

  // The following is an optimization because the symbol table can give a
  // more specific function class, so this can result in fewer polymorphic
  // function calls as the function gets called for each value of the array.
  {
    if (func.is_function_handle ())
      {
        octave_fcn_handle *f = func.fcn_handle_value ();

        // Overloaded function handles need to check the type of the
        // arguments for each element of the array, so they cannot be
        // optimized this way.
        if (f -> is_overloaded ())
          goto nevermind;
      }

    std::string name = func.function_value () -> name ();
    octave_value f = symtab.find_function (name);

    if (f.is_defined ())
      {
        // Except for these two which are special cases...
        if (name != "size" && name != "class")
          {
            // Try first the optimized code path for built-in functions
            octave_value_list tmp_args = args;
            tmp_args(0) = name;

            if (uniform_output)
              retval =
                try_cellfun_internal_ops<boolNDArray, NDArray> (tmp_args,
                                                                nargin);
            else
              retval =
                try_cellfun_internal_ops<Cell, Cell> (tmp_args, nargin);

            if (! retval.empty ())
              return retval;
          }

        // Okay, we tried, doesn't work, let's do the best we can instead
        // and avoid polymorphic calls for each element of the array.
        func = f;
      }
  }

nevermind:

  // Extract cell arguments.

  octave_value_list inputlist (nargin, octave_value ());

  OCTAVE_LOCAL_BUFFER (Cell, inputs, nargin);
  OCTAVE_LOCAL_BUFFER (bool, mask, nargin);

  // This is to prevent copy-on-write.
  const Cell *cinputs = inputs;

  octave_idx_type k = 1;

  dim_vector fdims (1, 1);

  // Collect arguments.  Pre-fill scalar elements of inputlist array.

  for (int j = 0; j < nargin; j++)
    {
      if (! args(j+1).iscell ())
        error ("cellfun: arguments must be cells");

      inputs[j] = args(j+1).cell_value ();
      mask[j] = inputs[j].numel () != 1;
      if (! mask[j])
        inputlist(j) = cinputs[j](0);
    }

  for (int j = 0; j < nargin; j++)
    {
      if (mask[j])
        {
          fdims = inputs[j].dims ();
          k = inputs[j].numel ();
          for (int i = j+1; i < nargin; i++)
            {
              if (mask[i] && inputs[i].dims () != fdims)
                error ("cellfun: dimensions mismatch");
            }
          break;
        }
    }

  octave::unwind_protect frame;
  frame.protect_var (buffer_error_messages);

  if (error_handler.is_defined ())
    buffer_error_messages++;

  // Apply functions.

  if (uniform_output)
    {
      std::list<octave_value_list> idx_list (1);
      idx_list.front ().resize (1);
      std::string idx_type = "(";

      OCTAVE_LOCAL_BUFFER (octave_value, retv, nargout1);

      for (octave_idx_type count = 0; count < k; count++)
        {
          for (int j = 0; j < nargin; j++)
            {
              if (mask[j])
                inputlist.xelem (j) = cinputs[j](count);
            }

          const octave_value_list tmp
            = get_output_list (count, nargout, inputlist, func,
                               error_handler);

          if (nargout > 0 && tmp.length () < nargout)
            error ("cellfun: function returned fewer than nargout values");

          if (nargout > 0
              || (nargout == 0
                  && tmp.length () > 0 && tmp(0).is_defined ()))
            {
              int num_to_copy = tmp.length ();

              if (num_to_copy > nargout1)
                num_to_copy = nargout1;

              if (count == 0)
                {
                  for (int j = 0; j < num_to_copy; j++)
                    {
                      if (tmp(j).is_defined ())
                        {
                          octave_value val = tmp(j);

                          if (val.numel () != 1)
                            error ("cellfun: all values must be scalars when UniformOutput = true");

                          retv[j] = val.resize (fdims);
                        }
                    }
                }
              else
                {
                  for (int j = 0; j < num_to_copy; j++)
                    {
                      if (tmp(j).is_defined ())
                        {
                          octave_value val = tmp(j);

                          if (! retv[j].fast_elem_insert (count, val))
                            {
                              if (val.numel () != 1)
                                error ("cellfun: all values must be scalars when UniformOutput = true");

                              idx_list.front ()(0) = count + 1.0;
                              retv[j].assign (octave_value::op_asn_eq,
                                              idx_type, idx_list, val);
                            }
                        }
                    }
                }
            }
        }

      retval.resize (nargout1);

      for (int j = 0; j < nargout1; j++)
        {
          if (nargout > 0 && retv[j].is_undefined ())
            retval(j) = NDArray (fdims);
          else
            retval(j) = retv[j];
        }
    }
  else
    {
      OCTAVE_LOCAL_BUFFER (Cell, results, nargout1);

      for (int j = 0; j < nargout1; j++)
        results[j].resize (fdims, Matrix ());

      bool have_some_output = false;

      for (octave_idx_type count = 0; count < k; count++)
        {
          for (int j = 0; j < nargin; j++)
            {
              if (mask[j])
                inputlist.xelem (j) = cinputs[j](count);
            }

          const octave_value_list tmp
            = get_output_list (count, nargout, inputlist, func,
                               error_handler);

          if (nargout > 0 && tmp.length () < nargout)
            error ("cellfun: function returned fewer than nargout values");

          if (nargout > 0
              || (nargout == 0
                  && tmp.length () > 0 && tmp(0).is_defined ()))
            {
              int num_to_copy = tmp.length ();

              if (num_to_copy > nargout1)
                num_to_copy = nargout1;

              if (num_to_copy > 0)
                have_some_output = true;

              for (int j = 0; j < num_to_copy; j++)
                results[j](count) = tmp(j);
            }
        }

      if (have_some_output || fdims.any_zero ())
        {
          retval.resize (nargout1);

          for (int j = 0; j < nargout1; j++)
            retval(j) = results[j];
        }
    }

  return retval;
}

/*

%!function r = __f11 (x)
%!  global __cellfun_test_num_outputs__;
%!  __cellfun_test_num_outputs__ = nargout;
%!  r = x;
%!endfunction

%!function __f01 (x)
%!  global __cellfun_test_num_outputs__;
%!  __cellfun_test_num_outputs__ = nargout;
%!endfunction

%!test
%! global __cellfun_test_num_outputs__;
%! cellfun (@__f11, {1});
%! assert (__cellfun_test_num_outputs__, 0);
%! x = cellfun (@__f11, {1});
%! assert (__cellfun_test_num_outputs__, 1);

%!test
%! global __cellfun_test_num_outputs__;
%! cellfun (@__f01, {1});
%! assert (__cellfun_test_num_outputs__, 0);

%!error x = cellfun (@__f01, {1, 2})

%!test
%! assert (cellfun (@__f11, {1, 2}), [1, 2]);
%! assert (cellfun (@__f11, {1, 2}, 'uniformoutput', false), {1, 2});

%!test
%! [a,b] = cellfun (@(x) x, cell (2, 0));
%! assert (a, zeros (2, 0));
%! assert (b, zeros (2, 0));

%!test
%! [a,b] = cellfun (@(x) x, cell (2, 0), "uniformoutput", false);
%! assert (a, cell (2, 0));
%! assert (b, cell (2, 0));

## Test function to check the "Errorhandler" option
%!function z = __cellfunerror (S, varargin)
%!  z = S;
%!endfunction

## First input argument can be a string, an inline function,
## a function_handle or an anonymous function
%!test
%! A = cellfun ("islogical", {true, 0.1, false, i*2});
%! assert (A, [true, false, true, false]);
%!test
%! A = cellfun (inline ("islogical (x)", "x"), {true, 0.1, false, i*2});
%! assert (A, [true, false, true, false]);
%!test
%! A = cellfun (@islogical, {true, 0.1, false, i*2});
%! assert (A, [true, false, true, false]);
%!test
%! A = cellfun (@(x) islogical (x), {true, 0.1, false, i*2});
%! assert (A, [true, false, true, false]);

## First input argument can be the special string "isreal",
## "isempty", "islogical", "isnumeric", "length", "ndims" or "prodofsize"
%!test
%! A = cellfun ("isreal", {true, 0.1, {}, i*2, [], "abc"});
%! assert (A, [true, true, false, false, true, true]);
%!test
%! A = cellfun ("isempty", {true, 0.1, false, i*2, [], "abc"});
%! assert (A, [false, false, false, false, true, false]);
%!test
%! A = cellfun ("islogical", {true, 0.1, false, i*2, [], "abc"});
%! assert (A, [true, false, true, false, false, false]);
%!test
%! A = cellfun ("isnumeric", {true, 0.1, false, i*2, [], "abc"});
%! assert (A, [false, true, false, true, true, false]);
%!test
%! A = cellfun ("length", {true, 0.1, false, i*2, [], "abc"});
%! assert (A, [1, 1, 1, 1, 0, 3]);
%!test
%! A = cellfun ("ndims", {[1, 2; 3, 4]; (cell (1,2,3,4))});
%! assert (A, [2; 4]);
%!test
%! A = cellfun ("prodofsize", {[1, 2; 3, 4], (cell (1,2,3,4))});
%! assert (A, [4, 24]);

## Number of input and output arguments may not be limited to one
%!test
%! A = cellfun (@(x,y,z) x + y + z, {1, 1, 1}, {2, 2, 2}, {3, 4, 5});
%! assert (A, [6, 7, 8]);
%!test
%! A = cellfun (@(x,y,z) x + y + z, {1, 1, 1}, {2, 2, 2}, {3, 4, 5}, ...
%!              "UniformOutput", false);
%! assert (A, {6, 7, 8});
%!test  # Two input arguments of different types
%! A = cellfun (@(x,y) islogical (x) && ischar (y), {false, true}, {"a", 3});
%! assert (A, [true, false]);
%!test  # Pass another variable to the anonymous function
%! y = true;
%! A = cellfun (@(x) islogical (x) && y, {false, 0.3});
%! assert (A, [true, false]);
%!test  # Three ouptut arguments of different type
%! [A, B, C] = cellfun (@find, {10, 11; 0, 12}, "UniformOutput", false);
%! assert (isequal (A, {true, true; [], true}));
%! assert (isequal (B, {true, true; [], true}));
%! assert (isequal (C, {10, 11; [], 12}));

## Input arguments can be of type cell array of logical
%!test
%! A = cellfun (@(x,y) x == y, {false, true}, {true, true});
%! assert (A, [false, true]);
%!test
%! A = cellfun (@(x,y) x == y, {false; true}, {true; true}, ...
%!              "UniformOutput", true);
%! assert (A, [false; true]);
%!test
%! A = cellfun (@(x) x, {false, true; false, true}, "UniformOutput", false);
%! assert (A, {false, true; false, true});
%!test  # Three ouptut arguments of same type
%! [A, B, C] = cellfun (@find, {true, false; false, true}, ...
%!                      "UniformOutput", false);
%! assert (isequal (A, {true, []; [], true}));
%! assert (isequal (B, {true, []; [], true}));
%! assert (isequal (C, {true, []; [], true}));
%!test
%! A = cellfun (@(x,y) cell2str (x,y), {true}, {true}, ...
%!              "ErrorHandler", @__cellfunerror);
%! assert (isfield (A, "identifier"), true);
%! assert (isfield (A, "message"), true);
%! assert (isfield (A, "index"), true);
%! assert (isempty (A.message), false);
%! assert (A.index, 1);
%!test  # Overwriting setting of "UniformOutput" true
%! A = cellfun (@(x,y) cell2str (x,y), {true}, {true}, ...
%!              "UniformOutput", true, "ErrorHandler", @__cellfunerror);
%! assert (isfield (A, "identifier"), true);
%! assert (isfield (A, "message"), true);
%! assert (isfield (A, "index"), true);
%! assert (isempty (A.message), false);
%! assert (A.index, 1);

## Input arguments can be of type cell array of numeric
%!test
%! A = cellfun (@(x,y) x>y, {1.1, 4.2}, {3.1, 2+3*i});
%! assert (A, [false, true]);
%!test
%! A = cellfun (@(x,y) x>y, {1.1, 4.2; 2, 4}, {3.1, 2; 2, 4+2*i}, ...
%!              "UniformOutput", true);
%! assert (A, [false, true; false, false]);
%!test
%! A = cellfun (@(x,y) x:y, {1.1, 4}, {3.1, 6}, "UniformOutput", false);
%! assert (isequal (A{1}, [1.1, 2.1, 3.1]));
%! assert (isequal (A{2}, [4, 5, 6]));
%!test  # Three ouptut arguments of different type
%! [A, B, C] = cellfun (@find, {10, 11; 0, 12}, "UniformOutput", false);
%! assert (isequal (A, {true, true; [], true}));
%! assert (isequal (B, {true, true; [], true}));
%! assert (isequal (C, {10, 11; [], 12}));
%!test
%! A = cellfun (@(x,y) cell2str (x,y), {1.1, 4}, {3.1, 6}, ...
%!              "ErrorHandler", @__cellfunerror);
%! B = isfield (A(1), "message") && isfield (A(1), "index");
%! assert ([(isfield (A(1), "identifier")), (isfield (A(2), "identifier"))], [true, true]);
%! assert ([(isfield (A(1), "message")), (isfield (A(2), "message"))], [true, true]);
%! assert ([(isfield (A(1), "index")), (isfield (A(2), "index"))], [true, true]);
%! assert ([(isempty (A(1).message)), (isempty (A(2).message))], [false, false]);
%! assert ([A(1).index, A(2).index], [1, 2]);
%!test  # Overwriting setting of "UniformOutput" true
%! A = cellfun (@(x,y) cell2str (x,y), {1.1, 4}, {3.1, 6}, ...
%!              "UniformOutput", true, "ErrorHandler", @__cellfunerror);
%! B = isfield (A(1), "message") && isfield (A(1), "index");
%! assert ([(isfield (A(1), "identifier")), (isfield (A(2), "identifier"))], [true, true]);
%! assert ([(isfield (A(1), "message")), (isfield (A(2), "message"))], [true, true]);
%! assert ([(isfield (A(1), "index")), (isfield (A(2), "index"))], [true, true]);
%! assert ([(isempty (A(1).message)), (isempty (A(2).message))], [false, false]);
%! assert ([A(1).index, A(2).index], [1, 2]);

## Input arguments can be of type cell arrays of character or strings
%!error  # "UniformOutput" false should be used
%! A = cellfun (@(x,y) x>y, {"ad", "c", "ghi"}, {"cc", "d", "fgh"});
%!test
%! A = cellfun (@(x,y) x>y, {"a"; "f"}, {"c"; "d"}, "UniformOutput", true);
%! assert (A, [false; true]);
%!test
%! A = cellfun (@(x,y) x:y, {"a", "d"}, {"c", "f"}, "UniformOutput", false);
%! assert (A, {"abc", "def"});
%!test
%! A = cellfun (@(x,y) cell2str (x,y), {"a", "d"}, {"c", "f"}, ...
%!              "ErrorHandler", @__cellfunerror);
%! assert ([(isfield (A(1), "identifier")), (isfield (A(2), "identifier"))], [true, true]);
%! assert ([(isfield (A(1), "message")), (isfield (A(2), "message"))], [true, true]);
%! assert ([(isfield (A(1), "index")), (isfield (A(2), "index"))], [true, true]);
%! assert ([(isempty (A(1).message)), (isempty (A(2).message))], [false, false]);
%! assert ([A(1).index, A(2).index], [1, 2]);
%!test  # Overwriting setting of "UniformOutput" true
%! A = cellfun (@(x,y) cell2str (x,y), {"a", "d"}, {"c", "f"}, ...
%!              "UniformOutput", true, "ErrorHandler", @__cellfunerror);
%! assert ([(isfield (A(1), "identifier")), (isfield (A(2), "identifier"))], [true, true]);
%! assert ([(isfield (A(1), "message")), (isfield (A(2), "message"))], [true, true]);
%! assert ([(isfield (A(1), "index")), (isfield (A(2), "index"))], [true, true]);
%! assert ([(isempty (A(1).message)), (isempty (A(2).message))], [false, false]);
%! assert ([A(1).index, A(2).index], [1, 2]);

## Structures cannot be handled by cellfun
%!error
%! vst1.a = 1.1;  vst1.b = 4.2;  vst2.a = 3.1;  vst2.b = 2;
%! A = cellfun (@(x,y) (x.a < y.a) && (x.b > y.b), vst1, vst2);

## Input arguments can be of type cell array of cell arrays
%!test
%! A = cellfun (@(x,y) x{1} < y{1}, {{1.1}, {4.2}}, {{3.1}, {2}});
%! assert (A, [1, 0], 1e-16);
%!test
%! A = cellfun (@(x,y) x{1} < y{1}, {{1.1}; {4.2}}, {{3.1}; {2}}, ...
%!              "UniformOutput", true);
%! assert (A, [1; 0], 1e-16);
%!test
%! A = cellfun (@(x,y) x{1} < y{1}, {{1.1}, {4.2}}, {{3.1}, {2}}, ...
%!              "UniformOutput", false);
%! assert (A, {true, false});
%!test
%! A = cellfun (@(x,y) mat2str (x,y), {{1.1}, {4.2}}, {{3.1}, {2}}, ...
%!              "ErrorHandler", @__cellfunerror);
%! assert ([(isfield (A(1), "identifier")), (isfield (A(2), "identifier"))], [true, true]);
%! assert ([(isfield (A(1), "message")), (isfield (A(2), "message"))], [true, true]);
%! assert ([(isfield (A(1), "index")), (isfield (A(2), "index"))], [true, true]);
%! assert ([(isempty (A(1).message)), (isempty (A(2).message))], [false, false]);
%! assert ([A(1).index, A(2).index], [1, 2]);
%!test  # Overwriting setting of "UniformOutput" true
%! A = cellfun (@(x,y) mat2str (x,y), {{1.1}, {4.2}}, {{3.1}, {2}}, ...
%!              "UniformOutput", true, "ErrorHandler", @__cellfunerror);
%! assert ([(isfield (A(1), "identifier")), (isfield (A(2), "identifier"))], [true, true]);
%! assert ([(isfield (A(1), "message")), (isfield (A(2), "message"))], [true, true]);
%! assert ([(isfield (A(1), "index")), (isfield (A(2), "index"))], [true, true]);
%! assert ([(isempty (A(1).message)), (isempty (A(2).message))], [false, false]);
%! assert ([A(1).index, A(2).index], [1, 2]);

## Input arguments can be of type cell array of structure arrays
%!test
%! a = struct ("a", 1, "b", 2);  b = struct ("a", 1, "b", 3);
%! A = cellfun (@(x,y) (x.a == y.a) && (x.b < y.b), {a}, {b});
%! assert (A, true);
%!test
%! a = struct ("a", 1, "b", 2);  b = struct ("a", 1, "b", 3);
%! A = cellfun (@(x,y) (x.a == y.a) && (x.b < y.b) , {a}, {b}, ...
%!              "UniformOutput", true);
%! assert (A, true);
%!test
%! a = struct ("a", 1, "b", 2);  b = struct ("a", 1, "b", 3);
%! A = cellfun (@(x,y) (x.a == y.a) && (x.b < y.b) , {a}, {b}, ...
%!              "UniformOutput", false);
%! assert (A, {true});
%!test
%! a = struct ("a", 1, "b", 2);  b = struct ("a", 1, "b", 3);
%! A = cellfun (@(x,y) cell2str (x.a, y.a), {a}, {b}, ...
%!              "ErrorHandler", @__cellfunerror);
%! assert (isfield (A, "identifier"), true);
%! assert (isfield (A, "message"), true);
%! assert (isfield (A, "index"), true);
%! assert (isempty (A.message), false);
%! assert (A.index, 1);
%!test  # Overwriting setting of "UniformOutput" true
%! a = struct ("a", 1, "b", 2);  b = struct ("a", 1, "b", 3);
%! A = cellfun (@(x,y) cell2str (x.a, y.a), {a}, {b}, ...
%!              "UniformOutput", true, "ErrorHandler", @__cellfunerror);
%! assert (isfield (A, "identifier"), true);
%! assert (isfield (A, "message"), true);
%! assert (isfield (A, "index"), true);
%! assert (isempty (A.message), false);
%! assert (A.index, 1);

## A lot of other tests
%!assert (cellfun (@sin, {0,1}), sin ([0,1]))
%!assert (cellfun (inline ("sin (x)"), {0,1}), sin ([0,1]))
%!assert (cellfun ("sin", {0,1}), sin ([0,1]))
%!assert (cellfun ("isempty", {1,[]}), [false,true])
%!assert (cellfun ("islogical", {false,pi}), [true,false])
%!assert (cellfun ("isnumeric", {false,pi,struct()}), [false,true,false])
%!assert (cellfun ("isreal", {1i,1}), [false,true])
%!assert (cellfun ("length", {zeros(2,2),1}), [2,1])
%!assert (cellfun ("prodofsize", {zeros(2,2),1}), [4,1])
%!assert (cellfun ("ndims", {zeros([2,2,2]),1}), [3,2])
%!assert (cellfun ("isclass", {zeros([2,2,2]),"test"}, "double"), [true,false])
%!assert (cellfun ("size", {zeros([1,2,3]),1}, 1), [1,1])
%!assert (cellfun ("size", {zeros([1,2,3]),1}, 2), [2,1])
%!assert (cellfun ("size", {zeros([1,2,3]),1}, 3), [3,1])
%!assert (cellfun (@atan2, {1,1}, {1,2}), [atan2(1,1), atan2(1,2)])
%!assert (cellfun (@atan2, {1,1}, {1,2},"UniformOutput", false), {atan2(1,1), atan2(1,2)})
%!assert (cellfun (@sin, {1,2;3,4}), sin ([1,2;3,4]))
%!assert (cellfun (@atan2, {1,1;1,1}, {1,2;1,2}), atan2 ([1,1;1,1],[1,2;1,2]))
%!error cellfun (@factorial, {-1,3})
%!assert (cellfun (@factorial,{-1,3},"ErrorHandler",@(x,y) NaN), [NaN,6])
%!assert (cellfun (@(x) x(2),{[1],[1,2]},"ErrorHandler",@(x,y) NaN), [NaN,2])
%!test
%! [a,b,c] = cellfun (@fileparts, {fullfile("a","b","c.d"), fullfile("e","f","g.h")}, "UniformOutput", false);
%! assert (a, {fullfile("a","b"), fullfile("e","f")});
%! assert (b, {"c", "g"});
%! assert (c, {".d", ".h"});

%!assert <*40467> (cellfun (@isreal, {1 inf nan []}), [true, true, true, true])
%!assert <*40467> (cellfun (@isreal, {1 inf nan []}, "UniformOutput", false), {true, true, true, true})
%!assert <*40467> (cellfun (@iscomplex, {1 inf nan []}), [false, false, false, false])
%!assert <*40467> (cellfun (@iscomplex, {1 inf nan []}, "UniformOutput", false), {false, false, false, false})

%!error cellfun (1)
%!error cellfun ("isclass", 1)
%!error cellfun ("size", 1)
%!error cellfun (@sin, {[]}, "BadParam", false)
%!error cellfun (@sin, {[]}, "UniformOuput")
%!error cellfun (@sin, {[]}, "ErrorHandler")
*/

// Arrayfun was originally a .m file written by Bill Denney and Jaroslav
// Hajek.  It was converted to C++ by jwe so that it could properly
// handle the nargout = 0 case.

DEFMETHOD (arrayfun, interp, args, nargout,
           doc: /* -*- texinfo -*-
@deftypefn  {} {} arrayfun (@var{func}, @var{A})
@deftypefnx {} {@var{x} =} arrayfun (@var{func}, @var{A})
@deftypefnx {} {@var{x} =} arrayfun (@var{func}, @var{A}, @var{b}, @dots{})
@deftypefnx {} {[@var{x}, @var{y}, @dots{}] =} arrayfun (@var{func}, @var{A}, @dots{})
@deftypefnx {} {} arrayfun (@dots{}, "UniformOutput", @var{val})
@deftypefnx {} {} arrayfun (@dots{}, "ErrorHandler", @var{errfunc})

Execute a function on each element of an array.

This is useful for functions that do not accept array arguments.  If the
function does accept array arguments it is better to call the function
directly.

The first input argument @var{func} can be a string, a function
handle, an inline function, or an anonymous function.  The input
argument @var{A} can be a logic array, a numeric array, a string
array, a structure array, or a cell array.  By a call of the function
@code{arrayfun} all elements of @var{A} are passed on to the named
function @var{func} individually.

The named function can also take more than two input arguments, with
the input arguments given as third input argument @var{b}, fourth
input argument @var{c}, @dots{}  If given more than one array input
argument then all input arguments must have the same sizes, for
example:

@example
@group
arrayfun (@@atan2, [1, 0], [0, 1])
     @result{} [ 1.57080   0.00000 ]
@end group
@end example

If the parameter @var{val} after a further string input argument
@qcode{"UniformOutput"} is set @code{true} (the default), then the named
function @var{func} must return a single element which then will be
concatenated into the return value and is of type matrix.  Otherwise,
if that parameter is set to @code{false}, then the outputs are
concatenated in a cell array.  For example:

@example
@group
arrayfun (@@(x,y) x:y, "abc", "def", "UniformOutput", false)
@result{}
   @{
     [1,1] = abcd
     [1,2] = bcde
     [1,3] = cdef
   @}
@end group
@end example

If more than one output arguments are given then the named function
must return the number of return values that also are expected, for
example:

@example
@group
[A, B, C] = arrayfun (@@find, [10; 0], "UniformOutput", false)
@result{}
A =
@{
   [1,1] =  1
   [2,1] = [](0x0)
@}
B =
@{
   [1,1] =  1
   [2,1] = [](0x0)
@}
C =
@{
   [1,1] =  10
   [2,1] = [](0x0)
@}
@end group
@end example

If the parameter @var{errfunc} after a further string input argument
@qcode{"ErrorHandler"} is another string, a function handle, an inline
function, or an anonymous function, then @var{errfunc} defines a
function to call in the case that @var{func} generates an error.
The definition of the function must be of the form

@example
function [@dots{}] = errfunc (@var{s}, @dots{})
@end example

@noindent
where there is an additional input argument to @var{errfunc}
relative to @var{func}, given by @var{s}.  This is a structure with
the elements @qcode{"identifier"}, @qcode{"message"}, and
@qcode{"index"} giving, respectively, the error identifier, the error
message, and the index of the array elements that caused the error.  The
size of the output argument of @var{errfunc} must have the same size as the
output argument of @var{func}, otherwise a real error is thrown.  For
example:

@example
@group
function y = ferr (s, x), y = "MyString"; endfunction
arrayfun (@@str2num, [1234],
          "UniformOutput", false, "ErrorHandler", @@ferr)
@result{}
   @{
     [1,1] = MyString
   @}
@end group
@end example

@seealso{spfun, cellfun, structfun}
@end deftypefn */)
{
  int nargin = args.length ();

  if (nargin < 2)
    print_usage ();

  octave_value_list retval;
  int nargout1 = (nargout < 1 ? 1 : nargout);
  bool symbol_table_lookup = false;
  octave_value func = args(0);

  octave::symbol_table& symtab = interp.get_symbol_table ();

  if (func.is_string ())
    {
      // See if we can convert the string into a function.
      std::string name = args(0).string_value ();

      if (! valid_identifier (name))
        {
          std::string fcn_name = unique_symbol_name ("__arrayfun_fcn__");
          std::string fname = "function y = " + fcn_name + "(x) y = ";

          octave_function *ptr_func
            = extract_function (args(0), "arrayfun", fcn_name,
                                fname, "; endfunction");

          if (ptr_func)
            func = octave_value (ptr_func, true);
        }
      else
        {
          func = symtab.find_function (name);

          if (func.is_undefined ())
            error_with_id ("Octave:invalid-input-arg",
                           "arrayfun: invalid function NAME: %s",
                           name.c_str ());

          symbol_table_lookup = true;
        }
    }

  if (func.is_function_handle () || func.is_inline_function ()
      || func.is_function ())
    {
      // The following is an optimization because the symbol table can give a
      // more specific function class, so this can result in fewer polymorphic
      // function calls as the function gets called for each value of the array.

      if (! symbol_table_lookup)
        {
          if (func.is_function_handle ())
            {
              octave_fcn_handle *f = func.fcn_handle_value ();

              // Overloaded function handles need to check the type of the
              // arguments for each element of the array, so they cannot be
              // optimized this way.
              if (f -> is_overloaded ())
                goto nevermind;
            }
          octave_value f
            = symtab.find_function (func.function_value () -> name ());

          if (f.is_defined ())
            func = f;
        }

    nevermind:

      bool uniform_output = true;
      octave_value error_handler;

      get_mapper_fun_options (symtab, args, nargin, uniform_output,
                              error_handler);

      octave_value_list inputlist (nargin, octave_value ());

      OCTAVE_LOCAL_BUFFER (octave_value, inputs, nargin);
      OCTAVE_LOCAL_BUFFER (bool, mask, nargin);

      octave_idx_type k = 1;

      dim_vector fdims (1, 1);

      // Collect arguments.  Pre-fill scalar elements of inputlist array.

      for (int j = 0; j < nargin; j++)
        {
          inputs[j] = args(j+1);
          mask[j] = inputs[j].numel () != 1;

          if (! mask[j])
            inputlist(j) = inputs[j];
        }

      for (int j = 0; j < nargin; j++)
        {
          if (mask[j])
            {
              fdims = inputs[j].dims ();
              k = inputs[j].numel ();

              for (int i = j+1; i < nargin; i++)
                {
                  if (mask[i] && inputs[i].dims () != fdims)
                    error_with_id ("Octave:invalid-input-arg",
                                   "arrayfun: dimensions mismatch");
                }
              break;
            }
        }

      octave::unwind_protect frame;
      frame.protect_var (buffer_error_messages);

      if (error_handler.is_defined ())
        buffer_error_messages++;

      // Apply functions.

      if (uniform_output)
        {
          std::list<octave_value_list> idx_list (1);
          idx_list.front ().resize (1);
          std::string idx_type = "(";

          OCTAVE_LOCAL_BUFFER (octave_value, retv, nargout1);

          for (octave_idx_type count = 0; count < k; count++)
            {
              idx_list.front ()(0) = count + 1.0;

              for (int j = 0; j < nargin; j++)
                {
                  if (mask[j])
                    inputlist.xelem (j) = inputs[j].do_index_op (idx_list);
                }

              const octave_value_list tmp
                = get_output_list (count, nargout, inputlist, func,
                                   error_handler);

              if (nargout > 0 && tmp.length () < nargout)
                error_with_id ("Octave:invalid-fun-call",
                               "arrayfun: function returned fewer than nargout values");

              if (nargout > 0
                  || (nargout == 0
                      && tmp.length () > 0 && tmp(0).is_defined ()))
                {
                  int num_to_copy = tmp.length ();

                  if (num_to_copy > nargout1)
                    num_to_copy = nargout1;

                  if (count == 0)
                    {
                      for (int j = 0; j < num_to_copy; j++)
                        {
                          if (tmp(j).is_defined ())
                            {
                              octave_value val = tmp(j);

                              if (val.numel () == 1)
                                retv[j] = val.resize (fdims);
                              else
                                error_with_id ("Octave:invalid-fun-call",
                                               "arrayfun: all values must be scalars when UniformOutput = true");
                            }
                        }
                    }
                  else
                    {
                      for (int j = 0; j < num_to_copy; j++)
                        {
                          if (tmp(j).is_defined ())
                            {
                              octave_value val = tmp(j);

                              if (! retv[j].fast_elem_insert (count, val))
                                {
                                  if (val.numel () == 1)
                                    {
                                      idx_list.front ()(0) = count + 1.0;
                                      retv[j].assign (octave_value::op_asn_eq,
                                                      idx_type, idx_list, val);
                                    }
                                  else
                                    error_with_id ("Octave:invalid-fun-call",
                                                   "arrayfun: all values must be scalars when UniformOutput = true");
                                }
                            }
                        }
                    }
                }
            }

          retval.resize (nargout1);

          for (int j = 0; j < nargout1; j++)
            {
              if (nargout > 0 && retv[j].is_undefined ())
                retval(j) = NDArray (fdims);
              else
                retval(j) = retv[j];
            }
        }
      else
        {
          std::list<octave_value_list> idx_list (1);
          idx_list.front ().resize (1);
          std::string idx_type = "(";

          OCTAVE_LOCAL_BUFFER (Cell, results, nargout1);

          for (int j = 0; j < nargout1; j++)
            results[j].resize (fdims, Matrix ());

          bool have_some_output = false;

          for (octave_idx_type count = 0; count < k; count++)
            {
              idx_list.front ()(0) = count + 1.0;

              for (int j = 0; j < nargin; j++)
                {
                  if (mask[j])
                    inputlist.xelem (j) = inputs[j].do_index_op (idx_list);
                }

              const octave_value_list tmp
                = get_output_list (count, nargout, inputlist, func,
                                   error_handler);

              if (nargout > 0 && tmp.length () < nargout)
                error_with_id ("Octave:invalid-fun-call",
                               "arrayfun: function returned fewer than nargout values");

              if (nargout > 0
                  || (nargout == 0
                      && tmp.length () > 0 && tmp(0).is_defined ()))
                {
                  int num_to_copy = tmp.length ();

                  if (num_to_copy > nargout1)
                    num_to_copy = nargout1;

                  if (num_to_copy > 0)
                    have_some_output = true;

                  for (int j = 0; j < num_to_copy; j++)
                    results[j](count) = tmp(j);
                }
            }

          if (have_some_output || fdims.any_zero ())
            {
              retval.resize (nargout1);

              for (int j = 0; j < nargout1; j++)
                retval(j) = results[j];
            }
        }
    }
  else
    error_with_id ("Octave:invalid-fun-call",
                   "arrayfun: argument NAME must be a string or function handle");

  return retval;
}

/*
%!function r = __f11 (x)
%!  global __arrayfun_test_num_outputs__;
%!  __arrayfun_test_num_outputs__ = nargout;
%!  r = x;
%!endfunction

%!function __f01 (x)
%!  global __arrayfun_test_num_outputs__;
%!  __arrayfun_test_num_outputs__ = nargout;
%!endfunction

%!test
%! global __arrayfun_test_num_outputs__;
%! arrayfun (@__f11, {1});
%! assert (__arrayfun_test_num_outputs__, 0);
%! x = arrayfun (@__f11, {1});
%! assert (__arrayfun_test_num_outputs__, 1);

%!test
%! global __arrayfun_test_num_outputs__;
%! arrayfun (@__f01, {1});
%! assert (__arrayfun_test_num_outputs__, 0);

%!error x = arrayfun (@__f01, [1, 2])

%!test
%! assert (arrayfun (@__f11, [1, 2]), [1, 2]);
%! assert (arrayfun (@__f11, [1, 2], "uniformoutput", false), {1, 2});
%! assert (arrayfun (@__f11, {1, 2}), {1, 2});
%! assert (arrayfun (@__f11, {1, 2}, "uniformoutput", false), {{1}, {2}});

%!assert (arrayfun (@ones, 1, [2,3], "uniformoutput", false), {[1,1], [1,1,1]})

## Test function to check the "Errorhandler" option
%!function z = __arrayfunerror (S, varargin)
%!  z = S;
%!endfunction
## First input argument can be a string, an inline function, a
## function_handle or an anonymous function
%!test
%! arrayfun (@isequal, [false, true], [true, true]);  # No output argument
%!error
%! arrayfun (@isequal);  # One or less input arguments
%!test
%! A = arrayfun ("isequal", [false, true], [true, true]);
%! assert (A, [false, true]);
%!test
%! A = arrayfun (inline ("(x == y)", "x", "y"), [false, true], [true, true]);
%! assert (A, [false, true]);
%!test
%! A = arrayfun (@isequal, [false, true], [true, true]);
%! assert (A, [false, true]);
%!test
%! A = arrayfun (@(x,y) isequal (x,y), [false, true], [true, true]);
%! assert (A, [false, true]);

## Number of input and output arguments may be greater than one
%!test
%! A = arrayfun (@(x) islogical (x), false);
%! assert (A, true);
%!test
%! A = arrayfun (@(x,y,z) x + y + z, [1, 1, 1], [2, 2, 2], [3, 4, 5]);
%! assert (A, [6, 7, 8], 1e-16);
%!test  # Two input arguments of different types
%! A = arrayfun (@(x,y) islogical (x) && ischar (y), false, "a");
%! assert (A, true);
%!test  # Pass another variable to the anonymous function
%! y = true;
%! A = arrayfun (@(x) islogical (x && y), false);
%! assert (A, true);
%!test  # Three ouptut arguments of different type
%! [A, B, C] = arrayfun (@find, [10, 11; 0, 12], "UniformOutput", false);
%! assert (isequal (A, {true, true; [], true}));
%! assert (isequal (B, {true, true; [], true}));
%! assert (isequal (C, {10, 11; [], 12}));

## Input arguments can be of type logical
%!test
%! A = arrayfun (@(x,y) x == y, [false, true], [true, true]);
%! assert (A, [false, true]);
%!test
%! A = arrayfun (@(x,y) x == y, [false; true], [true; true], "UniformOutput", true);
%! assert (A, [false; true]);
%!test
%! A = arrayfun (@(x) x, [false, true, false, true], "UniformOutput", false);
%! assert (A, {false, true, false, true});
%!test  # Three ouptut arguments of same type
%! [A, B, C] = arrayfun (@find, [true, false; false, true], "UniformOutput", false);
%! assert (isequal (A, {true, []; [], true}));
%! assert (isequal (B, {true, []; [], true}));
%! assert (isequal (C, {true, []; [], true}));
%!test
%! A = arrayfun (@(x,y) array2str (x,y), true, true, ...
%!               "ErrorHandler", @__arrayfunerror);
%! assert (isfield (A, "identifier"), true);
%! assert (isfield (A, "message"), true);
%! assert (isfield (A, "index"), true);
%! assert (isempty (A.message), false);
%! assert (A.index, 1);
%!test  # Overwriting setting of "UniformOutput" true
%! A = arrayfun (@(x,y) array2str (x,y), true, true, "UniformOutput", true, ...
%!               "ErrorHandler", @__arrayfunerror);
%! assert (isfield (A, "identifier"), true);
%! assert (isfield (A, "message"), true);
%! assert (isfield (A, "index"), true);
%! assert (isempty (A.message), false);
%! assert (A.index, 1);

## Input arguments can be of type numeric
%!test
%! A = arrayfun (@(x,y) x>y, [1.1, 4.2], [3.1, 2+3*i]);
%! assert (A, [false, true]);
%!test
%! A = arrayfun (@(x,y) x>y, [1.1, 4.2; 2, 4], [3.1, 2; 2, 4+2*i], "UniformOutput", true);
%! assert (A, [false, true; false, false]);
%!test
%! A = arrayfun (@(x,y) x:y, [1.1, 4], [3.1, 6], "UniformOutput", false);
%! assert (isequal (A{1}, [1.1, 2.1, 3.1]));
%! assert (isequal (A{2}, [4, 5, 6]));
%!test  # Three ouptut arguments of different type
%! [A, B, C] = arrayfun (@find, [10, 11; 0, 12], "UniformOutput", false);
%! assert (isequal (A, {true, true; [], true}));
%! assert (isequal (B, {true, true; [], true}));
%! assert (isequal (C, {10, 11; [], 12}));
%!test
%! A = arrayfun (@(x,y) array2str (x,y), {1.1, 4}, {3.1, 6}, ...
%!               "ErrorHandler", @__arrayfunerror);
%! B = isfield (A(1), "message") && isfield (A(1), "index");
%! assert ([(isfield (A(1), "identifier")), (isfield (A(2), "identifier"))], [true, true]);
%! assert ([(isfield (A(1), "message")), (isfield (A(2), "message"))], [true, true]);
%! assert ([(isfield (A(1), "index")), (isfield (A(2), "index"))], [true, true]);
%! assert ([(isempty (A(1).message)), (isempty (A(2).message))], [false, false]);
%! assert ([A(1).index, A(2).index], [1, 2]);
%!test  # Overwriting setting of "UniformOutput" true
%! A = arrayfun (@(x,y) array2str (x,y), {1.1, 4}, {3.1, 6}, ...
%!               "UniformOutput", true, "ErrorHandler", @__arrayfunerror);
%! B = isfield (A(1), "message") && isfield (A(1), "index");
%! assert ([(isfield (A(1), "identifier")), (isfield (A(2), "identifier"))], [true, true]);
%! assert ([(isfield (A(1), "message")), (isfield (A(2), "message"))], [true, true]);
%! assert ([(isfield (A(1), "index")), (isfield (A(2), "index"))], [true, true]);
%! assert ([(isempty (A(1).message)), (isempty (A(2).message))], [false, false]);
%! assert ([A(1).index, A(2).index], [1, 2]);

## Input arguments can be of type character or strings
%!test
%! A = arrayfun (@(x,y) x>y, ["ad", "c", "ghi"], ["cc", "d", "fgh"]);
%! assert (A, [false, true, false, true, true, true]);
%!test
%! A = arrayfun (@(x,y) x>y, ["a"; "f"], ["c"; "d"], "UniformOutput", true);
%! assert (A, [false; true]);
%!test
%! A = arrayfun (@(x,y) x:y, ["a", "d"], ["c", "f"], "UniformOutput", false);
%! assert (A, {"abc", "def"});
%!test
%! A = arrayfun (@(x,y) cell2str (x,y), ["a", "d"], ["c", "f"], ...
%!               "ErrorHandler", @__arrayfunerror);
%! B = isfield (A(1), "identifier") && isfield (A(1), "message") && isfield (A(1), "index");
%! assert (B, true);

## Input arguments can be of type structure
%!test
%! a = struct ("a", 1.1, "b", 4.2);  b = struct ("a", 3.1, "b", 2);
%! A = arrayfun (@(x,y) (x.a < y.a) && (x.b > y.b), a, b);
%! assert (A, true);
%!test
%! a = struct ("a", 1.1, "b", 4.2);  b = struct ("a", 3.1, "b", 2);
%! A = arrayfun (@(x,y) (x.a < y.a) && (x.b > y.b), a, b, "UniformOutput", true);
%! assert (A, true);
%!test
%! a = struct ("a", 1.1, "b", 4.2);  b = struct ("a", 3.1, "b", 2);
%! A = arrayfun (@(x,y) x.a:y.a, a, b, "UniformOutput", false);
%! assert (isequal (A, {[1.1, 2.1, 3.1]}));
%!test
%! A = arrayfun (@(x) mat2str(x), "a", "ErrorHandler", @__arrayfunerror);
%! assert (isfield (A, "identifier"), true);
%! assert (isfield (A, "message"), true);
%! assert (isfield (A, "index"), true);
%! assert (isempty (A.message), false);
%! assert (A.index, 1);
%!test  # Overwriting setting of "UniformOutput" true
%! A = arrayfun (@(x) mat2str(x), "a", "UniformOutput", true, ...
%!               "ErrorHandler", @__arrayfunerror);
%! assert (isfield (A, "identifier"), true);
%! assert (isfield (A, "message"), true);
%! assert (isfield (A, "index"), true);
%! assert (isempty (A.message), false);
%! assert (A.index, 1);

## Input arguments can be of type cell array
%!test
%! A = arrayfun (@(x,y) x{1} < y{1}, {1.1, 4.2}, {3.1, 2});
%! assert (A, [true, false]);
%!test
%! A = arrayfun (@(x,y) x{1} < y{1}, {1.1; 4.2}, {3.1; 2}, "UniformOutput", true);
%! assert (A, [true; false]);
%!test
%! A = arrayfun (@(x,y) x{1} < y{1}, {1.1, 4.2}, {3.1, 2}, "UniformOutput", false);
%! assert (A, {true, false});
%!test
%! A = arrayfun (@(x,y) num2str(x,y), {1.1, 4.2}, {3.1, 2}, "ErrorHandler", @__arrayfunerror);
%! assert ([(isfield (A(1), "identifier")), (isfield (A(2), "identifier"))], [true, true]);
%! assert ([(isfield (A(1), "message")), (isfield (A(2), "message"))], [true, true]);
%! assert ([(isfield (A(1), "index")), (isfield (A(2), "index"))], [true, true]);
%! assert ([(isempty (A(1).message)), (isempty (A(2).message))], [false, false]);
%! assert ([A(1).index, A(2).index], [1, 2]);
%!test
%! A = arrayfun (@(x,y) num2str (x,y), {1.1, 4.2}, {3.1, 2}, ...
%!               "UniformOutput", true, "ErrorHandler", @__arrayfunerror);
%! assert ([(isfield (A(1), "identifier")), (isfield (A(2), "identifier"))], [true, true]);
%! assert ([(isfield (A(1), "message")), (isfield (A(2), "message"))], [true, true]);
%! assert ([(isfield (A(1), "index")), (isfield (A(2), "index"))], [true, true]);
%! assert ([(isempty (A(1).message)), (isempty (A(2).message))], [false, false]);
%! assert ([A(1).index, A(2).index], [1, 2]);
*/

static void
do_num2cell_helper (const dim_vector& dv,
                    const Array<int>& dimv,
                    dim_vector& celldv, dim_vector& arraydv,
                    Array<int>& perm)
{
  int dvl = dimv.numel ();
  int maxd = dv.ndims ();
  celldv = dv;
  for (int i = 0; i < dvl; i++)
    maxd = std::max (maxd, dimv(i));
  if (maxd > dv.ndims ())
    celldv.resize (maxd, 1);
  arraydv = celldv;

  OCTAVE_LOCAL_BUFFER_INIT (bool, sing, maxd, false);

  perm.clear (maxd, 1);
  for (int i = 0; i < dvl; i++)
    {
      int k = dimv(i) - 1;
      if (k < 0)
        error ("num2cell: dimension indices must be positive");

      if (i > 0 && k < dimv(i-1) - 1)
        error ("num2cell: dimension indices must be strictly increasing");

      sing[k] = true;
      perm(i) = k;
    }

  for (int k = 0, i = dvl; k < maxd; k++)
    if (! sing[k])
      perm(i++) = k;

  for (int i = 0; i < maxd; i++)
    if (sing[i])
      celldv(i) = 1;
    else
      arraydv(i) = 1;
}

template <typename NDA>
static inline typename NDA::element_type
do_num2cell_elem (const NDA& array, octave_idx_type i)
{ return array(i); }

static inline Cell
do_num2cell_elem (const Cell& array, octave_idx_type i)
{ return Cell (array(i)); }

template <typename NDA>
static Cell
do_num2cell (const NDA& array, const Array<int>& dimv)
{
  if (dimv.isempty ())
    {
      Cell retval (array.dims ());
      octave_idx_type nel = array.numel ();
      for (octave_idx_type i = 0; i < nel; i++)
        retval.xelem (i) = do_num2cell_elem (array, i);

      return retval;
    }
  else
    {
      dim_vector celldv, arraydv;
      Array<int> perm;
      do_num2cell_helper (array.dims (), dimv, celldv, arraydv, perm);

      NDA parray = array.permute (perm);

      octave_idx_type nela = arraydv.numel ();
      octave_idx_type nelc = celldv.numel ();
      parray = parray.reshape (dim_vector (nela, nelc));

      Cell retval (celldv);
      for (octave_idx_type i = 0; i < nelc; i++)
        {
          retval.xelem (i) = NDA (parray.column (i).reshape (arraydv));
        }

      return retval;
    }
}

// FIXME: this is a mess, but if a size method for the object exists,
// we have to call it to get the size of the object instead of using the
// internal dims method.

static dim_vector
get_object_dims (octave_value& obj)
{
  dim_vector retval;

  Matrix m = obj.size ();

  int n = m.numel ();

  retval.resize (n);

  for (int i = 0; i < n; i++)
    retval(i) = m(i);

  return retval;
}

static Cell
do_object2cell (const octave_value& obj, const Array<int>& dimv)
{
  Cell retval;

  // FIXME: this copy is only needed because the octave_value::size
  // method is not const.
  octave_value array = obj;

  if (! dimv.isempty ())
    error ("num2cell (A, dim) not implemented for class objects");

  dim_vector dv = get_object_dims (array);

  retval.resize (dv);

  octave_value_list idx (1);

  for (octave_idx_type i = 0; i < dv.numel (); i++)
    {
      octave_quit ();

      idx(0) = double (i+1);

      retval.xelem (i) = array.single_subsref ("(", idx);
    }

  return retval;
}

DEFUN (num2cell, args, ,
       doc: /* -*- texinfo -*-
@deftypefn  {} {@var{C} =} num2cell (@var{A})
@deftypefnx {} {@var{C} =} num2cell (@var{A}, @var{dim})
Convert the numeric matrix @var{A} to a cell array.

If @var{dim} is defined, the value @var{C} is of dimension 1 in this
dimension and the elements of @var{A} are placed into @var{C} in slices.
For example:

@example
@group
num2cell ([1,2;3,4])
   @result{}
      @{
        [1,1] =  1
        [2,1] =  3
        [1,2] =  2
        [2,2] =  4
      @}
num2cell ([1,2;3,4],1)
   @result{}
      @{
        [1,1] =
           1
           3
        [1,2] =
           2
           4
      @}
@end group
@end example

@seealso{mat2cell}
@end deftypefn */)
{
  int nargin = args.length ();

  if (nargin < 1 || nargin > 2)
    print_usage ();

  octave_value retval;

  octave_value array = args(0);

  Array<int> dimv;
  if (nargin > 1)
    dimv = args(1).int_vector_value (true);

  if (array.islogical ())
    retval = do_num2cell (array.bool_array_value (), dimv);
  else if (array.is_char_matrix ())
    retval = do_num2cell (array.char_array_value (), dimv);
  else if (array.isnumeric ())
    {
      if (array.isinteger ())
        {
          if (array.is_int8_type ())
            retval = do_num2cell (array.int8_array_value (), dimv);
          else if (array.is_int16_type ())
            retval = do_num2cell (array.int16_array_value (), dimv);
          else if (array.is_int32_type ())
            retval = do_num2cell (array.int32_array_value (), dimv);
          else if (array.is_int64_type ())
            retval = do_num2cell (array.int64_array_value (), dimv);
          else if (array.is_uint8_type ())
            retval = do_num2cell (array.uint8_array_value (), dimv);
          else if (array.is_uint16_type ())
            retval = do_num2cell (array.uint16_array_value (), dimv);
          else if (array.is_uint32_type ())
            retval = do_num2cell (array.uint32_array_value (), dimv);
          else if (array.is_uint64_type ())
            retval = do_num2cell (array.uint64_array_value (), dimv);
        }
      else if (array.iscomplex ())
        {
          if (array.is_single_type ())
            retval = do_num2cell (array.float_complex_array_value (), dimv);
          else
            retval = do_num2cell (array.complex_array_value (), dimv);
        }
      else
        {
          if (array.is_single_type ())
            retval = do_num2cell (array.float_array_value (), dimv);
          else
            retval = do_num2cell (array.array_value (), dimv);
        }
    }
  else if (array.isobject ())
    retval = do_object2cell (array, dimv);
  else if (array.isstruct ())
    retval = do_num2cell (array.map_value (), dimv);
  else if (array.iscell ())
    retval = do_num2cell (array.cell_value (), dimv);
  else
    err_wrong_type_arg ("num2cell", array);

  return retval;
}

/*
%!assert (num2cell ([1,2;3,4]), {1,2;3,4})
%!assert (num2cell ([1,2;3,4], 1), {[1;3],[2;4]})
%!assert (num2cell ([1,2;3,4], 2), {[1,2];[3,4]})
*/

static bool
mat2cell_mismatch (const dim_vector& dv,
                   const Array<octave_idx_type> *d, int nd)
{
  for (int i = 0; i < nd; i++)
    {
      octave_idx_type s = 0;
      for (octave_idx_type j = 0; j < d[i].numel (); j++)
        s += d[i](j);

      octave_idx_type r = (i < dv.ndims () ? dv(i) : 1);

      if (s != r)
        error ("mat2cell: mismatch on dimension %d (%d != %d)", i+1, r, s);
    }

  return false;
}

template <typename container>
static void
prepare_idx (container *idx, int idim, int nd,
             const Array<octave_idx_type>* d)
{
  octave_idx_type nidx = (idim < nd ? d[idim].numel () : 1);
  if (nidx == 1)
    idx[0] = idx_vector::colon;
  else
    {
      octave_idx_type l = 0;
      for (octave_idx_type i = 0; i < nidx; i++)
        {
          octave_idx_type u = l + d[idim](i);
          idx[i] = idx_vector (l, u);
          l = u;
        }
    }
}

// 2D specialization, works for Array, Sparse and octave_map.
// Uses 1D or 2D indexing.

template <typename Array2D>
static Cell
do_mat2cell_2d (const Array2D& a, const Array<octave_idx_type> *d, int nd)
{
  NoAlias<Cell> retval;
  assert (nd == 1 || nd == 2);
  assert (a.ndims () == 2);

  if (mat2cell_mismatch (a.dims (), d, nd))
    return retval;

  octave_idx_type nridx = d[0].numel ();
  octave_idx_type ncidx = (nd == 1 ? 1 : d[1].numel ());
  retval.clear (nridx, ncidx);

  int ivec = -1;
  if (a.rows () > 1 && a.cols () == 1 && ncidx == 1)
    ivec = 0;
  else if (a.rows () == 1 && nridx == 1 && nd == 2)
    ivec = 1;

  if (ivec >= 0)
    {
      // Vector split.  Use 1D indexing.
      octave_idx_type l = 0;
      octave_idx_type nidx = (ivec == 0 ? nridx : ncidx);
      for (octave_idx_type i = 0; i < nidx; i++)
        {
          octave_idx_type u = l + d[ivec](i);
          retval(i) = a.index (idx_vector (l, u));
          l = u;
        }
    }
  else
    {
      // General 2D case.  Use 2D indexing.
      OCTAVE_LOCAL_BUFFER (idx_vector, ridx, nridx);
      prepare_idx (ridx, 0, nd, d);

      OCTAVE_LOCAL_BUFFER (idx_vector, cidx, ncidx);
      prepare_idx (cidx, 1, nd, d);

      for (octave_idx_type j = 0; j < ncidx; j++)
        for (octave_idx_type i = 0; i < nridx; i++)
          {
            octave_quit ();

            retval(i,j) = a.index (ridx[i], cidx[j]);
          }
    }

  return retval;
}

// Nd case.  Works for Arrays and octave_map.
// Uses Nd indexing.

template <typename ArrayND>
Cell
do_mat2cell_nd (const ArrayND& a, const Array<octave_idx_type> *d, int nd)
{
  NoAlias<Cell> retval;
  assert (nd >= 1);

  if (mat2cell_mismatch (a.dims (), d, nd))
    return retval;

  dim_vector rdv = dim_vector::alloc (nd);
  OCTAVE_LOCAL_BUFFER (octave_idx_type, nidx, nd);
  octave_idx_type idxtot = 0;
  for (int i = 0; i < nd; i++)
    {
      rdv(i) = nidx[i] = d[i].numel ();
      idxtot += nidx[i];
    }

  retval.clear (rdv);

  OCTAVE_LOCAL_BUFFER (idx_vector, xidx, idxtot);
  OCTAVE_LOCAL_BUFFER (idx_vector *, idx, nd);

  idxtot = 0;
  for (int i = 0; i < nd; i++)
    {
      idx[i] = xidx + idxtot;
      prepare_idx (idx[i], i, nd, d);
      idxtot += nidx[i];
    }

  OCTAVE_LOCAL_BUFFER_INIT (octave_idx_type, ridx, nd, 0);
  NoAlias< Array<idx_vector>> ra_idx
    (dim_vector (1, std::max (nd, a.ndims ())), idx_vector::colon);

  for (octave_idx_type j = 0; j < retval.numel (); j++)
    {
      octave_quit ();

      for (int i = 0; i < nd; i++)
        ra_idx(i) = idx[i][ridx[i]];

      retval(j) = a.index (ra_idx);

      rdv.increment_index (ridx);
    }

  return retval;
}

// Dispatcher.
template <typename ArrayND>
Cell
do_mat2cell (const ArrayND& a, const Array<octave_idx_type> *d, int nd)
{
  if (a.ndims () == 2 && nd <= 2)
    return do_mat2cell_2d (a, d, nd);
  else
    return do_mat2cell_nd (a, d, nd);
}

// General case.  Works for any class supporting do_index_op.
// Uses Nd indexing.

Cell
do_mat2cell (octave_value& a, const Array<octave_idx_type> *d, int nd)
{
  NoAlias<Cell> retval;
  assert (nd >= 1);

  if (mat2cell_mismatch (a.dims (), d, nd))
    return retval;

  dim_vector rdv = dim_vector::alloc (nd);
  OCTAVE_LOCAL_BUFFER (octave_idx_type, nidx, nd);
  octave_idx_type idxtot = 0;
  for (int i = 0; i < nd; i++)
    {
      rdv(i) = nidx[i] = d[i].numel ();
      idxtot += nidx[i];
    }

  retval.clear (rdv);

  OCTAVE_LOCAL_BUFFER (octave_value, xidx, idxtot);
  OCTAVE_LOCAL_BUFFER (octave_value *, idx, nd);

  idxtot = 0;
  for (int i = 0; i < nd; i++)
    {
      idx[i] = xidx + idxtot;
      prepare_idx (idx[i], i, nd, d);
      idxtot += nidx[i];
    }

  OCTAVE_LOCAL_BUFFER_INIT (octave_idx_type, ridx, nd, 0);
  octave_value_list ra_idx (std::max (nd, a.ndims ()),
                            octave_value::magic_colon_t);

  for (octave_idx_type j = 0; j < retval.numel (); j++)
    {
      octave_quit ();

      for (int i = 0; i < nd; i++)
        ra_idx(i) = idx[i][ridx[i]];

      retval(j) = a.do_index_op (ra_idx);

      rdv.increment_index (ridx);
    }

  return retval;
}

DEFUN (mat2cell, args, ,
       doc: /* -*- texinfo -*-
@deftypefn  {} {@var{C} =} mat2cell (@var{A}, @var{m}, @var{n})
@deftypefnx {} {@var{C} =} mat2cell (@var{A}, @var{d1}, @var{d2}, @dots{})
@deftypefnx {} {@var{C} =} mat2cell (@var{A}, @var{r})
Convert the matrix @var{A} to a cell array.

If @var{A} is 2-D, then it is required that
@code{sum (@var{m}) == size (@var{A}, 1)} and
@code{sum (@var{n}) == size (@var{A}, 2)}.  Similarly, if @var{A} is
multi-dimensional and the number of dimensional arguments is equal to the
dimensions of @var{A}, then it is required that
@code{sum (@var{di}) == size (@var{A}, i)}.

Given a single dimensional argument @var{r}, the other dimensional
arguments are assumed to equal @code{size (@var{A},@var{i})}.

An example of the use of mat2cell is

@example
mat2cell (reshape (1:16,4,4), [3,1], [3,1])
@result{}
@{
   [1,1] =

      1   5   9
      2   6  10
      3   7  11

   [2,1] =

      4   8  12

   [1,2] =

     13
     14
     15

   [2,2] = 16
@}
@end example
@seealso{num2cell, cell2mat}
@end deftypefn */)
{
  int nargin = args.length ();

  if (nargin < 2)
    print_usage ();

  octave_value retval;

  // Prepare indices.
  OCTAVE_LOCAL_BUFFER (Array<octave_idx_type>, d, nargin-1);

  for (int i = 1; i < nargin; i++)
    d[i-1] = args(i).octave_idx_type_vector_value (true);

  octave_value a = args(0);
  bool sparse = a.issparse ();
  if (sparse && nargin > 3)
    error ("mat2cell: sparse arguments only support 2-D indexing");

  switch (a.builtin_type ())
    {
    case btyp_double:
      {
        if (sparse)
          retval = do_mat2cell_2d (a.sparse_matrix_value (), d, nargin-1);
        else
          retval = do_mat2cell (a.array_value (), d, nargin - 1);
      }
      break;

    case btyp_complex:
      {
        if (sparse)
          retval = do_mat2cell_2d (a.sparse_complex_matrix_value (), d,
                                   nargin-1);
        else
          retval = do_mat2cell (a.complex_array_value (), d, nargin - 1);
      }
      break;

#define BTYP_BRANCH(X, Y)                                       \
      case btyp_ ## X:                                          \
        retval = do_mat2cell (a.Y ## _value (), d, nargin - 1); \
        break

      BTYP_BRANCH (float, float_array);
      BTYP_BRANCH (float_complex, float_complex_array);
      BTYP_BRANCH (bool, bool_array);
      BTYP_BRANCH (char, char_array);

      BTYP_BRANCH (int8,  int8_array);
      BTYP_BRANCH (int16, int16_array);
      BTYP_BRANCH (int32, int32_array);
      BTYP_BRANCH (int64, int64_array);
      BTYP_BRANCH (uint8,  uint8_array);
      BTYP_BRANCH (uint16, uint16_array);
      BTYP_BRANCH (uint32, uint32_array);
      BTYP_BRANCH (uint64, uint64_array);

      BTYP_BRANCH (cell, cell);
      BTYP_BRANCH (struct, map);

#undef BTYP_BRANCH

    case btyp_func_handle:
      err_wrong_type_arg ("mat2cell", a);
      break;

    default:
      retval = do_mat2cell (a, d, nargin-1);
      break;
    }

  return retval;
}

/*
%!test
%! x = reshape (1:20, 5, 4);
%! c = mat2cell (x, [3,2], [3,1]);
%! assert (c, {[1,6,11;2,7,12;3,8,13],[16;17;18];[4,9,14;5,10,15],[19;20]});

%!test
%! x = "abcdefghij";
%! c = mat2cell (x, 1, [0,4,2,0,4,0]);
%! empty1by0str = resize ("", 1, 0);
%! assert (c, {empty1by0str,"abcd","ef",empty1by0str,"ghij",empty1by0str});
*/

// FIXME: it would be nice to allow ranges being handled without a conversion.
template <typename NDA>
static Cell
do_cellslices_nda (const NDA& array,
                   const Array<octave_idx_type>& lb,
                   const Array<octave_idx_type>& ub,
                   int dim = -1)
{
  octave_idx_type n = lb.numel ();
  Cell retval (1, n);
  if (array.isvector () && (dim == -1
                            || (dim == 0 && array.columns () == 1)
                            || (dim == 1 && array.rows () == 1)))
    {
      for (octave_idx_type i = 0; i < n; i++)
        retval(i) = array.index (idx_vector (lb(i) - 1, ub(i)));
    }
  else
    {
      const dim_vector dv = array.dims ();
      int ndims = dv.ndims ();
      if (dim < 0)
        dim = dv.first_non_singleton ();
      ndims = std::max (ndims, dim + 1);

      Array<idx_vector> idx (dim_vector (ndims, 1), idx_vector::colon);

      for (octave_idx_type i = 0; i < n; i++)
        {
          idx(dim) = idx_vector (lb(i) - 1, ub(i));
          retval(i) = array.index (idx);
        }
    }

  return retval;
}

DEFUN (cellslices, args, ,
       doc: /* -*- texinfo -*-
@deftypefn {} {@var{sl} =} cellslices (@var{x}, @var{lb}, @var{ub}, @var{dim})
Given an array @var{x}, this function produces a cell array of slices from
the array determined by the index vectors @var{lb}, @var{ub}, for lower and
upper bounds, respectively.

In other words, it is equivalent to the following code:

@example
@group
n = length (lb);
sl = cell (1, n);
for i = 1:length (lb)
  sl@{i@} = x(:,@dots{},lb(i):ub(i),@dots{},:);
endfor
@end group
@end example

The position of the index is determined by @var{dim}.  If not specified,
slicing is done along the first non-singleton dimension.
@seealso{cell2mat, cellindexmat, cellfun}
@end deftypefn */)
{
  int nargin = args.length ();

  if (nargin < 3 || nargin > 4)
    print_usage ();

  octave_value x = args(0);
  Array<octave_idx_type> lb = args(1).octave_idx_type_vector_value ();
  Array<octave_idx_type> ub = args(2).octave_idx_type_vector_value ();
  int dim = -1;
  if (nargin == 4)
    {
      dim = args(3).int_value () - 1;
      if (dim < 0)
        error ("cellslices: DIM must be a valid dimension");
    }

  if (lb.numel () != ub.numel ())
    error ("cellslices: the lengths of LB and UB must match");

  Cell retcell;
  if (! x.issparse () && x.is_matrix_type ())
    {
      // specialize for some dense arrays.
      if (x.islogical ())
        retcell = do_cellslices_nda (x.bool_array_value (),
                                     lb, ub, dim);
      else if (x.is_char_matrix ())
        retcell = do_cellslices_nda (x.char_array_value (),
                                     lb, ub, dim);
      else if (x.isinteger ())
        {
          if (x.is_int8_type ())
            retcell = do_cellslices_nda (x.int8_array_value (),
                                         lb, ub, dim);
          else if (x.is_int16_type ())
            retcell = do_cellslices_nda (x.int16_array_value (),
                                         lb, ub, dim);
          else if (x.is_int32_type ())
            retcell = do_cellslices_nda (x.int32_array_value (),
                                         lb, ub, dim);
          else if (x.is_int64_type ())
            retcell = do_cellslices_nda (x.int64_array_value (),
                                         lb, ub, dim);
          else if (x.is_uint8_type ())
            retcell = do_cellslices_nda (x.uint8_array_value (),
                                         lb, ub, dim);
          else if (x.is_uint16_type ())
            retcell = do_cellslices_nda (x.uint16_array_value (),
                                         lb, ub, dim);
          else if (x.is_uint32_type ())
            retcell = do_cellslices_nda (x.uint32_array_value (),
                                         lb, ub, dim);
          else if (x.is_uint64_type ())
            retcell = do_cellslices_nda (x.uint64_array_value (),
                                         lb, ub, dim);
        }
      else if (x.iscomplex ())
        {
          if (x.is_single_type ())
            retcell = do_cellslices_nda (x.float_complex_array_value (),
                                         lb, ub, dim);
          else
            retcell = do_cellslices_nda (x.complex_array_value (),
                                         lb, ub, dim);
        }
      else
        {
          if (x.is_single_type ())
            retcell = do_cellslices_nda (x.float_array_value (),
                                         lb, ub, dim);
          else
            retcell = do_cellslices_nda (x.array_value (),
                                         lb, ub, dim);
        }
    }
  else
    {
      // generic code.
      octave_idx_type n = lb.numel ();
      retcell = Cell (1, n);
      const dim_vector dv = x.dims ();
      int ndims = dv.ndims ();
      if (dim < 0)
        dim = dv.first_non_singleton ();
      ndims = std::max (ndims, dim + 1);
      octave_value_list idx (ndims, octave_value::magic_colon_t);
      for (octave_idx_type i = 0; i < n; i++)
        {
          idx(dim) = Range (lb(i), ub(i));
          retcell(i) = x.do_index_op (idx);
        }
    }

  return ovl (retcell);
}

/*
%!test
%! m = [1, 2, 3, 4; 5, 6, 7, 8; 9, 10, 11, 12];
%! c = cellslices (m, [1, 2], [2, 3], 2);
%! assert (c, {[1, 2; 5, 6; 9, 10], [2, 3; 6, 7; 10, 11]});
*/

DEFUN (cellindexmat, args, ,
       doc: /* -*- texinfo -*-
@deftypefn {} {@var{y} =} cellindexmat (@var{x}, @var{varargin})
Perform indexing of matrices in a cell array.

Given a cell array of matrices @var{x}, this function computes

@example
@group
Y = cell (size (X));
for i = 1:numel (X)
  Y@{i@} = X@{i@}(varargin@{1@}, varargin@{2@}, @dots{}, varargin@{N@});
endfor
@end group
@end example

The indexing arguments may be scalar (@code{2}), arrays (@code{[1, 3]}),
ranges (@code{1:3}), or the colon operator (@qcode{":"}).  However, the
indexing keyword @code{end} is not available.
@seealso{cellslices, cellfun}
@end deftypefn */)
{
  if (args.length () == 0)
    print_usage ();

  const Cell x = args(0).xcell_value ("cellindexmat: X must be a cell");

  NoAlias<Cell> y (x.dims ());
  octave_idx_type nel = x.numel ();
  octave_value_list idx = args.slice (1, args.length () - 1);

  for (octave_idx_type i = 0; i < nel; i++)
    {
      octave_quit ();

      octave_value tmp = x(i);

      y(i) = tmp.do_index_op (idx);
    }

  return octave_value (y);
}