**See also:**How do I search for a function?

# PDL::Ops

- NAME
- DESCRIPTION
- SYNOPSIS
- FUNCTIONS
- plus
- mult
- minus
- divide
- gt
- lt
- le
- ge
- eq
- ne
- shiftleft
- shiftright
- or2
- and2
- xor
- bitnot
- power
- atan2
- modulo
- spaceship
- sqrt
- abs
- sin
- cos
- not
- exp
- log
- log10
- assgn
- AUTHOR

# NAME

PDL::Ops - Fundamental mathematical operators

# DESCRIPTION

This module provides the functions used by PDL to
overload the basic mathematical operators (`+ - / *`

etc.) and functions (`sin sqrt`

etc.)

It also includes the function `log10`

, which should
be a perl function so that we can overload it!

Matrix multiplication (the operator `x`

) is handled
by the module PDL::Primitive.

# SYNOPSIS

none

# FUNCTIONS

## plus

Signature: (a(); b(); [o]c(); int swap)

add two piddles

$c = plus $a, $b, 0; # explicit call with trailing 0 $c = $a + $b; # overloaded call $a->inplace->plus($b,0); # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the binary `+`

operator.
Note that when calling this function explicitly you need to supply
a third argument that should generally be zero (see first example).
This restriction is expected to go away in future releases.

plus processes bad values. The state of the bad-value flag of the output piddles is unknown.

## mult

Signature: (a(); b(); [o]c(); int swap)

multiply two piddles

$c = mult $a, $b, 0; # explicit call with trailing 0 $c = $a * $b; # overloaded call $a->inplace->mult($b,0); # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the binary `*`

operator.
Note that when calling this function explicitly you need to supply
a third argument that should generally be zero (see first example).
This restriction is expected to go away in future releases.

mult processes bad values. The state of the bad-value flag of the output piddles is unknown.

## minus

Signature: (a(); b(); [o]c(); int swap)

subtract two piddles

$c = minus $a, $b, 0; # explicit call with trailing 0 $c = $a - $b; # overloaded call $a->inplace->minus($b,0); # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the binary `-`

operator.
Note that when calling this function explicitly you need to supply
a third argument that should generally be zero (see first example).
This restriction is expected to go away in future releases.

minus processes bad values. The state of the bad-value flag of the output piddles is unknown.

## divide

Signature: (a(); b(); [o]c(); int swap)

divide two piddles

$c = divide $a, $b, 0; # explicit call with trailing 0 $c = $a / $b; # overloaded call $a->inplace->divide($b,0); # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the binary `/`

operator.
Note that when calling this function explicitly you need to supply
a third argument that should generally be zero (see first example).
This restriction is expected to go away in future releases.

divide processes bad values. The state of the bad-value flag of the output piddles is unknown.

## gt

Signature: (a(); b(); [o]c(); int swap)

the binary > (greater than) operation

$c = gt $a, $b, 0; # explicit call with trailing 0 $c = $a > $b; # overloaded call $a->inplace->gt($b,0); # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the binary `>`

operator.
Note that when calling this function explicitly you need to supply
a third argument that should generally be zero (see first example).
This restriction is expected to go away in future releases.

gt processes bad values. The state of the bad-value flag of the output piddles is unknown.

## lt

Signature: (a(); b(); [o]c(); int swap)

the binary < (less than) operation

$c = lt $a, $b, 0; # explicit call with trailing 0 $c = $a < $b; # overloaded call $a->inplace->lt($b,0); # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the binary `<`

operator.
Note that when calling this function explicitly you need to supply
a third argument that should generally be zero (see first example).
This restriction is expected to go away in future releases.

lt processes bad values. The state of the bad-value flag of the output piddles is unknown.

## le

Signature: (a(); b(); [o]c(); int swap)

the binary <= (less equal) operation

$c = le $a, $b, 0; # explicit call with trailing 0 $c = $a <= $b; # overloaded call $a->inplace->le($b,0); # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the binary `<=`

operator.
Note that when calling this function explicitly you need to supply
a third argument that should generally be zero (see first example).
This restriction is expected to go away in future releases.

le processes bad values. The state of the bad-value flag of the output piddles is unknown.

## ge

Signature: (a(); b(); [o]c(); int swap)

the binary >= (greater equal) operation

$c = ge $a, $b, 0; # explicit call with trailing 0 $c = $a >= $b; # overloaded call $a->inplace->ge($b,0); # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the binary `>=`

operator.
Note that when calling this function explicitly you need to supply
a third argument that should generally be zero (see first example).
This restriction is expected to go away in future releases.

ge processes bad values. The state of the bad-value flag of the output piddles is unknown.

## eq

Signature: (a(); b(); [o]c(); int swap)

binary *equal to* operation (`==`

)

$c = eq $a, $b, 0; # explicit call with trailing 0 $c = $a == $b; # overloaded call $a->inplace->eq($b,0); # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the binary `==`

operator.
Note that when calling this function explicitly you need to supply
a third argument that should generally be zero (see first example).
This restriction is expected to go away in future releases.

eq processes bad values. The state of the bad-value flag of the output piddles is unknown.

## ne

Signature: (a(); b(); [o]c(); int swap)

binary *not equal to* operation (`!=`

)

$c = ne $a, $b, 0; # explicit call with trailing 0 $c = $a != $b; # overloaded call $a->inplace->ne($b,0); # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the binary `!=`

operator.
Note that when calling this function explicitly you need to supply
a third argument that should generally be zero (see first example).
This restriction is expected to go away in future releases.

ne processes bad values. The state of the bad-value flag of the output piddles is unknown.

## shiftleft

Signature: (a(); b(); [o]c(); int swap)

leftshift `$a`

by `$b`

$c = shiftleft $a, $b, 0; # explicit call with trailing 0 $c = $a << $b; # overloaded call $a->inplace->shiftleft($b,0); # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the binary `<<`

operator.
Note that when calling this function explicitly you need to supply
a third argument that should generally be zero (see first example).
This restriction is expected to go away in future releases.

shiftleft processes bad values. The state of the bad-value flag of the output piddles is unknown.

## shiftright

Signature: (a(); b(); [o]c(); int swap)

rightshift `$a`

by `$b`

$c = shiftright $a, $b, 0; # explicit call with trailing 0 $c = $a >> $b; # overloaded call $a->inplace->shiftright($b,0); # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the binary `>>`

operator.
Note that when calling this function explicitly you need to supply
a third argument that should generally be zero (see first example).
This restriction is expected to go away in future releases.

shiftright processes bad values. The state of the bad-value flag of the output piddles is unknown.

## or2

Signature: (a(); b(); [o]c(); int swap)

binary *or* of two piddles

$c = or2 $a, $b, 0; # explicit call with trailing 0 $c = $a | $b; # overloaded call $a->inplace->or2($b,0); # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the binary `|`

operator.
Note that when calling this function explicitly you need to supply
a third argument that should generally be zero (see first example).
This restriction is expected to go away in future releases.

or2 processes bad values. The state of the bad-value flag of the output piddles is unknown.

## and2

Signature: (a(); b(); [o]c(); int swap)

binary *and* of two piddles

$c = and2 $a, $b, 0; # explicit call with trailing 0 $c = $a & $b; # overloaded call $a->inplace->and2($b,0); # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the binary `&`

operator.
Note that when calling this function explicitly you need to supply
a third argument that should generally be zero (see first example).
This restriction is expected to go away in future releases.

and2 processes bad values. The state of the bad-value flag of the output piddles is unknown.

## xor

Signature: (a(); b(); [o]c(); int swap)

binary *exclusive or* of two piddles

$c = xor $a, $b, 0; # explicit call with trailing 0 $c = $a ^ $b; # overloaded call $a->inplace->xor($b,0); # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the binary `^`

operator.
Note that when calling this function explicitly you need to supply
a third argument that should generally be zero (see first example).
This restriction is expected to go away in future releases.

xor processes bad values. The state of the bad-value flag of the output piddles is unknown.

## bitnot

Signature: (a(); [o]b())

unary bit negation

$b = ~ $a; $a->inplace->bitnot; # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the unary `~`

operator/function.

bitnot processes bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.

## power

Signature: (a(); b(); [o]c(); int swap)

raise piddle `$a`

to the power `$b`

$c = $a->power($b,0); # explicit function call $c = $a ** $b; # overloaded use $a->inplace->power($b,0); # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the binary `**`

function.
Note that when calling this function explicitly you need to supply
a third argument that should generally be zero (see first example).
This restriction is expected to go away in future releases.

power processes bad values. The state of the bad-value flag of the output piddles is unknown.

## atan2

Signature: (a(); b(); [o]c(); int swap)

elementwise `atan2`

of two piddles

$c = $a->atan2($b,0); # explicit function call $c = atan2 $a, $b; # overloaded use $a->inplace->atan2($b,0); # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the binary `atan2`

function.
Note that when calling this function explicitly you need to supply
a third argument that should generally be zero (see first example).
This restriction is expected to go away in future releases.

atan2 processes bad values. The state of the bad-value flag of the output piddles is unknown.

## modulo

Signature: (a(); b(); [o]c(); int swap)

elementwise `modulo`

operation

$c = $a->modulo($b,0); # explicit function call $c = $a % $b; # overloaded use $a->inplace->modulo($b,0); # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the binary `%`

function.
Note that when calling this function explicitly you need to supply
a third argument that should generally be zero (see first example).
This restriction is expected to go away in future releases.

modulo processes bad values. The state of the bad-value flag of the output piddles is unknown.

## spaceship

Signature: (a(); b(); [o]c(); int swap)

elementwise "<=>" operation

$c = $a->spaceship($b,0); # explicit function call $c = $a <=> $b; # overloaded use $a->inplace->spaceship($b,0); # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the binary `<=>`

function.
Note that when calling this function explicitly you need to supply
a third argument that should generally be zero (see first example).
This restriction is expected to go away in future releases.

spaceship processes bad values. The state of the bad-value flag of the output piddles is unknown.

## sqrt

Signature: (a(); [o]b())

elementwise square root

$b = sqrt $a; $a->inplace->sqrt; # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the unary `sqrt`

operator/function.

sqrt processes bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.

## abs

Signature: (a(); [o]b())

elementwise absolute value

$b = abs $a; $a->inplace->abs; # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the unary `abs`

operator/function.

abs processes bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.

## sin

Signature: (a(); [o]b())

the sin function

$b = sin $a; $a->inplace->sin; # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the unary `sin`

operator/function.

sin processes bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.

## cos

Signature: (a(); [o]b())

the cos function

$b = cos $a; $a->inplace->cos; # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the unary `cos`

operator/function.

cos processes bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.

## not

Signature: (a(); [o]b())

the elementwise *not* operation

$b = ! $a; $a->inplace->not; # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the unary `!`

operator/function.

not processes bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.

## exp

Signature: (a(); [o]b())

the exponential function

$b = exp $a; $a->inplace->exp; # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the unary `exp`

operator/function.

exp processes bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.

## log

Signature: (a(); [o]b())

the natural logarithm

$b = log $a; $a->inplace->log; # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the unary `log`

operator/function.

log processes bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.

## log10

Signature: (a(); [o]b())

the base 10 logarithm

$b = log10 $a; $a->inplace->log10; # modify $a inplace

It can be made to work inplace with the `$a->inplace`

syntax.
This function is used to overload the unary `log10`

operator/function.

log10 processes bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.

## assgn

Signature: (a(); [o]b())

Plain numerical assignment. This is used to implement the ".=" operator

assgn does not process bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.

# AUTHOR

Tuomas J. Lukka (lukka@fas.harvard.edu), Karl Glazebrook (kgb@aaoepp.aao.gov.au), Doug Hunt (dhunt@ucar.edu), Christian Soeller (c.soeller@auckland.ac.nz), Doug Burke (burke@ifa.hawaii.edu), and Craig DeForest (deforest@boulder.swri.edu)