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Octave has a number of functions for managing sets of data. A set is defined
as a collection of unique elements and is typically represented by a vector of
numbers sorted in ascending order. Any vector or matrix can be converted to a
set by removing duplicates through the use of the `unique`

function.
However, it isn’t necessary to explicitly create a set as all of the functions
which operate on sets will convert their input to a set before proceeding.

- :
**unique***(*`x`) - :
**unique***(*`x`, "rows") - :
*[*`y`,`i`,`j`] =**unique***(…)* - :
*[*`y`,`i`,`j`] =**unique***(…, "first")* - :
*[*`y`,`i`,`j`] =**unique***(…, "last")* Return the unique elements of

`x`sorted in ascending order.If the input

`x`is a column vector then return a column vector; Otherwise, return a row vector.`x`may also be a cell array of strings.If the optional argument

`"rows"`

is given then return the unique rows of`x`sorted in ascending order. The input must be a 2-D matrix to use this option.If requested, return index vectors

`i`and`j`such that

and`y`=`x`(`i`)

.`x`=`y`(`j`)Additionally, if

`i`is a requested output then one of`"first"`

or`"last"`

may be given as an input. If`"last"`

is specified, return the highest possible indices in`i`, otherwise, if`"first"`

is specified, return the lowest. The default is`"last"`

.

• Set Operations: |

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