Ops(3pm)

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 ndarrays

   $c = $x + $y;        # overloaded call
   $c = plus $x, $y;     # explicit call with default swap of 0
   $c = plus $x, $y, 1;  # explicit call with trailing 1 to swap args
   $x->inplace->plus($y); # modify $x inplace

It can be made to work inplace with the "$x->inplace" syntax. This function is used to overload the binary "+" operator. As of 2.065, when calling this function explicitly you can omit the third argument (see second example), or supply it (see third one).

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

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

multiply two ndarrays

   $c = $x * $y;        # overloaded call
   $c = mult $x, $y;     # explicit call with default swap of 0
   $c = mult $x, $y, 1;  # explicit call with trailing 1 to swap args
   $x->inplace->mult($y); # modify $x inplace

It can be made to work inplace with the "$x->inplace" syntax. This function is used to overload the binary "*" operator. As of 2.065, when calling this function explicitly you can omit the third argument (see second example), or supply it (see third one).

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

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

subtract two ndarrays

   $c = $x - $y;        # overloaded call
   $c = minus $x, $y;     # explicit call with default swap of 0
   $c = minus $x, $y, 1;  # explicit call with trailing 1 to swap args
   $x->inplace->minus($y); # modify $x inplace

It can be made to work inplace with the "$x->inplace" syntax. This function is used to overload the binary "-" operator. As of 2.065, when calling this function explicitly you can omit the third argument (see second example), or supply it (see third one).

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

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

divide two ndarrays

   $c = $x / $y;        # overloaded call
   $c = divide $x, $y;     # explicit call with default swap of 0
   $c = divide $x, $y, 1;  # explicit call with trailing 1 to swap args
   $x->inplace->divide($y); # modify $x inplace

It can be made to work inplace with the "$x->inplace" syntax. This function is used to overload the binary "/" operator. As of 2.065, when calling this function explicitly you can omit the third argument (see second example), or supply it (see third one).

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

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

the binary > (greater than) operation

   $c = $x > $y;        # overloaded call
   $c = gt $x, $y;     # explicit call with default swap of 0
   $c = gt $x, $y, 1;  # explicit call with trailing 1 to swap args
   $x->inplace->gt($y); # modify $x inplace

It can be made to work inplace with the "$x->inplace" syntax. This function is used to overload the binary ">" operator. As of 2.065, when calling this function explicitly you can omit the third argument (see second example), or supply it (see third one).

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

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

the binary < (less than) operation

   $c = $x < $y;        # overloaded call
   $c = lt $x, $y;     # explicit call with default swap of 0
   $c = lt $x, $y, 1;  # explicit call with trailing 1 to swap args
   $x->inplace->lt($y); # modify $x inplace

It can be made to work inplace with the "$x->inplace" syntax. This function is used to overload the binary "<" operator. As of 2.065, when calling this function explicitly you can omit the third argument (see second example), or supply it (see third one).

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

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

the binary <= (less equal) operation

   $c = $x <= $y;        # overloaded call
   $c = le $x, $y;     # explicit call with default swap of 0
   $c = le $x, $y, 1;  # explicit call with trailing 1 to swap args
   $x->inplace->le($y); # modify $x inplace

It can be made to work inplace with the "$x->inplace" syntax. This function is used to overload the binary "<=" operator. As of 2.065, when calling this function explicitly you can omit the third argument (see second example), or supply it (see third one).

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

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

the binary >= (greater equal) operation

   $c = $x >= $y;        # overloaded call
   $c = ge $x, $y;     # explicit call with default swap of 0
   $c = ge $x, $y, 1;  # explicit call with trailing 1 to swap args
   $x->inplace->ge($y); # modify $x inplace

It can be made to work inplace with the "$x->inplace" syntax. This function is used to overload the binary ">=" operator. As of 2.065, when calling this function explicitly you can omit the third argument (see second example), or supply it (see third one).

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

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

binary equal to operation ("==")

   $c = $x == $y;        # overloaded call
   $c = eq $x, $y;     # explicit call with default swap of 0
   $c = eq $x, $y, 1;  # explicit call with trailing 1 to swap args
   $x->inplace->eq($y); # modify $x inplace

It can be made to work inplace with the "$x->inplace" syntax. This function is used to overload the binary "==" operator. As of 2.065, when calling this function explicitly you can omit the third argument (see second example), or supply it (see third one).

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

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

binary not equal to operation ("!=")

   $c = $x != $y;        # overloaded call
   $c = ne $x, $y;     # explicit call with default swap of 0
   $c = ne $x, $y, 1;  # explicit call with trailing 1 to swap args
   $x->inplace->ne($y); # modify $x inplace

It can be made to work inplace with the "$x->inplace" syntax. This function is used to overload the binary "!=" operator. As of 2.065, when calling this function explicitly you can omit the third argument (see second example), or supply it (see third one).

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

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

leftshift $a by $b

   $c = $x << $y;        # overloaded call
   $c = shiftleft $x, $y;     # explicit call with default swap of 0
   $c = shiftleft $x, $y, 1;  # explicit call with trailing 1 to swap args
   $x->inplace->shiftleft($y); # modify $x inplace

It can be made to work inplace with the "$x->inplace" syntax. This function is used to overload the binary "<<" operator. As of 2.065, when calling this function explicitly you can omit the third argument (see second example), or supply it (see third one).

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

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

rightshift $a by $b

   $c = $x >> $y;        # overloaded call
   $c = shiftright $x, $y;     # explicit call with default swap of 0
   $c = shiftright $x, $y, 1;  # explicit call with trailing 1 to swap args
   $x->inplace->shiftright($y); # modify $x inplace

It can be made to work inplace with the "$x->inplace" syntax. This function is used to overload the binary ">>" operator. As of 2.065, when calling this function explicitly you can omit the third argument (see second example), or supply it (see third one).

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

  or2
  Signature: (a(); b(); [o]c(); int swap)

binary or of two ndarrays

   $c = $x | $y;        # overloaded call
   $c = or2 $x, $y;     # explicit call with default swap of 0
   $c = or2 $x, $y, 1;  # explicit call with trailing 1 to swap args
   $x->inplace->or2($y); # modify $x inplace

It can be made to work inplace with the "$x->inplace" syntax. This function is used to overload the binary "|" operator. As of 2.065, when calling this function explicitly you can omit the third argument (see second example), or supply it (see third one).

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

  and2
  Signature: (a(); b(); [o]c(); int swap)

binary and of two ndarrays

   $c = $x & $y;        # overloaded call
   $c = and2 $x, $y;     # explicit call with default swap of 0
   $c = and2 $x, $y, 1;  # explicit call with trailing 1 to swap args
   $x->inplace->and2($y); # modify $x inplace

It can be made to work inplace with the "$x->inplace" syntax. This function is used to overload the binary "&" operator. As of 2.065, when calling this function explicitly you can omit the third argument (see second example), or supply it (see third one).

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

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

binary exclusive or of two ndarrays

   $c = $x ^ $y;        # overloaded call
   $c = xor $x, $y;     # explicit call with default swap of 0
   $c = xor $x, $y, 1;  # explicit call with trailing 1 to swap args
   $x->inplace->xor($y); # modify $x inplace

It can be made to work inplace with the "$x->inplace" syntax. This function is used to overload the binary "^" operator. As of 2.065, when calling this function explicitly you can omit the third argument (see second example), or supply it (see third one).

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

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

unary bit negation

   $y = ~ $x;
   $x->inplace->bitnot;  # modify $x inplace

It can be made to work inplace with the "$x->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 ndarrays if the flag is set for any of the input ndarrays.

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

raise ndarray $a to the power $b

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

It can be made to work inplace with the "$x->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 ndarrays is unknown.

  atan2
  Signature: (a(); b(); [o]c(); int swap)

elementwise "atan2" of two ndarrays

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

It can be made to work inplace with the "$x->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 ndarrays is unknown.

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

elementwise "modulo" operation

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

It can be made to work inplace with the "$x->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 ndarrays is unknown.

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

elementwise "<=>" operation

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

It can be made to work inplace with the "$x->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 ndarrays is unknown.

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

elementwise square root

   $y = sqrt $x;
   $x->inplace->sqrt;  # modify $x inplace

It can be made to work inplace with the "$x->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 ndarrays if the flag is set for any of the input ndarrays.

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

the sin function

   $y = sin $x;
   $x->inplace->sin;  # modify $x inplace

It can be made to work inplace with the "$x->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 ndarrays if the flag is set for any of the input ndarrays.

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

the cos function

   $y = cos $x;
   $x->inplace->cos;  # modify $x inplace

It can be made to work inplace with the "$x->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 ndarrays if the flag is set for any of the input ndarrays.

  not
  Signature: (a(); [o]b())

the elementwise not operation

   $y = ! $x;
   $x->inplace->not;  # modify $x inplace

It can be made to work inplace with the "$x->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 ndarrays if the flag is set for any of the input ndarrays.

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

the exponential function

   $y = exp $x;
   $x->inplace->exp;  # modify $x inplace

It can be made to work inplace with the "$x->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 ndarrays if the flag is set for any of the input ndarrays.

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

the natural logarithm

   $y = log $x;
   $x->inplace->log;  # modify $x inplace

It can be made to work inplace with the "$x->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 ndarrays if the flag is set for any of the input ndarrays.

  re
  Signature: (complexv(); real [o]b())

Returns the real part of a complex number.

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

  im
  Signature: (complexv(); real [o]b())

Returns the imaginary part of a complex number.

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

  _cabs
  Signature: (complexv(); real [o]b())

Returns the absolute (length) of a complex number.

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

  log10
  Signature: (a(); [o]b())

the base 10 logarithm

   $y = log10 $x;
   $x->inplace->log10;  # modify $x inplace

It can be made to work inplace with the "$x->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 ndarrays if the flag is set for any of the input ndarrays.

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

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

If "a" is a child ndarray (e.g., the result of a slice) and bad values are generated in "b", the bad value flag is set in "b", but it is NOT automatically propagated back to the parent of "a". The following idiom ensures that the badflag is propagated back to the parent of "a":

 $pdl->slice(":,(1)") .= PDL::Bad_aware_func();
 $pdl->badflag(1);
 $pdl->check_badflag();

This is unnecessary if $pdl->badflag is known to be 1 before the slice is performed.

See http://pdl.perl.org/PDLdocs/BadValues.html#dataflow_of_the_badflag for details.

  carg
  Signature: (complexv(); real [o]b())

Returns the polar angle of a complex number.

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

  conj
  Signature: (complexv();  [o]b())

complex conjugate.

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

  czip
  Signature: (r(); i(); complex [o]c())

convert real, imaginary to native complex, (sort of) like LISP zip function. Will add the "r" ndarray to "i" times the "i" ndarray. Only takes real ndarrays as input.

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

  ipow
  Signature: (a(); indx b(); [o] ans())

raise ndarray $a to integer power $b

   $c = $x->ipow($y,0);     # explicit function call
   $c = ipow $x, $y;
   $x->inplace->ipow($y,0);  # modify $x inplace

It can be made to work inplace with the "$x->inplace" syntax. 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.

Algorithm from Wikipedia <http://en.wikipedia.org/wiki/Exponentiation_by_squaring>

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

  abs
Returns the absolute value of a number.

  abs2
Returns the square of the absolute value of a number.

  r2C
  Signature: (r(); complex [o]c())

convert real to native complex, with an imaginary part of zero

r2C does not process bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.

  i2C
  Signature: (i(); complex [o]c())

convert imaginary to native complex, with a real part of zero

i2C does not process bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.

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).