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# PDL::Ops

# 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).