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Sum of elements along dimension dim.
If dim is omitted, it defaults to the first non-singleton dimension.
The optional "type"
input determines the class of the variable
used for calculations. By default, operations on floating point inputs (double
or single) are performed in their native data type, while operations on
integer, logical, and character data types are performed using doubles. If the
argument "native"
is given, then the operation is performed in the same
type as the original argument.
For example:
sum ([true, true]) ⇒ 2 sum ([true, true], "native") ⇒ true
If "double"
is given the sum is performed in double precision even for
single precision inputs.
For double precision inputs, the "extra"
option will use a more
accurate algorithm than straightforward summation. For single precision
inputs, "extra"
is the same as "double"
. For all other data
type "extra"
has no effect.
Product of elements along dimension dim.
If dim is omitted, it defaults to the first non-singleton dimension.
The optional "type"
input determines the class of the variable
used for calculations. If the argument "native"
is given, then
the operation is performed in the same type as the original argument, rather
than the default double type.
For example:
prod ([true, true]) ⇒ 1 prod ([true, true], "native") ⇒ true
On the contrary, if "double"
is given, the operation is performed
in double precision even for single precision inputs.
Cumulative sum of elements along dimension dim.
If dim is omitted, it defaults to the first non-singleton dimension. For example:
cumsum ([1, 2; 3, 4; 5, 6]) ⇒ 1 2 4 6 9 12
See sum
for an explanation of the optional parameters "native"
and "double"
.
Cumulative product of elements along dimension dim.
If dim is omitted, it defaults to the first non-singleton dimension. For example:
cumprod ([1, 2; 3, 4; 5, 6]) ⇒ 1 2 3 8 15 48
Sum of squares of elements along dimension dim.
If dim is omitted, it defaults to the first non-singleton dimension.
This function is conceptually equivalent to computing
sum (x .* conj (x), dim)
but it uses less memory and avoids calling conj
if x is real.
Next: Utility Functions, Previous: Trigonometry, Up: Arithmetic [Contents][Index]