Ops(3)

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
   $c = PDL::plus($x, $y);     # explicit call with default swap of 0
   $c = PDL::plus($x, $y, 0);  # explicit call with explicit swap of 0
   $c = PDL::plus($x, $y, 1);  # explicit call with trailing 1 to swap args
   PDL::plus($x, $y, $c, 1);   # all params given
   $x->plus($y, $c, 0);        # method call, all params given
   $c = $x->plus($y);          # method call
   $x->inplace->plus($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. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.

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

multiply two ndarrays

   $c = $x * $y;               # overloaded call
   $c = PDL::mult($x, $y);     # explicit call with default swap of 0
   $c = PDL::mult($x, $y, 0);  # explicit call with explicit swap of 0
   $c = PDL::mult($x, $y, 1);  # explicit call with trailing 1 to swap args
   PDL::mult($x, $y, $c, 1);   # all params given
   $x->mult($y, $c, 0);        # method call, all params given
   $c = $x->mult($y);          # method call
   $x->inplace->mult($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. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.

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

subtract two ndarrays

   $c = $x - $y;               # overloaded call
   $c = PDL::minus($x, $y);     # explicit call with default swap of 0
   $c = PDL::minus($x, $y, 0);  # explicit call with explicit swap of 0
   $c = PDL::minus($x, $y, 1);  # explicit call with trailing 1 to swap args
   PDL::minus($x, $y, $c, 1);   # all params given
   $x->minus($y, $c, 0);        # method call, all params given
   $c = $x->minus($y);          # method call
   $x->inplace->minus($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. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.

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

divide two ndarrays

   $c = $x / $y;               # overloaded call
   $c = PDL::divide($x, $y);     # explicit call with default swap of 0
   $c = PDL::divide($x, $y, 0);  # explicit call with explicit swap of 0
   $c = PDL::divide($x, $y, 1);  # explicit call with trailing 1 to swap args
   PDL::divide($x, $y, $c, 1);   # all params given
   $x->divide($y, $c, 0);        # method call, all params given
   $c = $x->divide($y);          # method call
   $x->inplace->divide($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. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.

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

the binary > (greater than) operation

   $c = $x > $y;               # overloaded call
   $c = PDL::gt($x, $y);     # explicit call with default swap of 0
   $c = PDL::gt($x, $y, 0);  # explicit call with explicit swap of 0
   $c = PDL::gt($x, $y, 1);  # explicit call with trailing 1 to swap args
   PDL::gt($x, $y, $c, 1);   # all params given
   $x->gt($y, $c, 0);        # method call, all params given
   $c = $x->gt($y);          # method call
   $x->inplace->gt($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. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.

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

the binary < (less than) operation

   $c = $x < $y;               # overloaded call
   $c = PDL::lt($x, $y);     # explicit call with default swap of 0
   $c = PDL::lt($x, $y, 0);  # explicit call with explicit swap of 0
   $c = PDL::lt($x, $y, 1);  # explicit call with trailing 1 to swap args
   PDL::lt($x, $y, $c, 1);   # all params given
   $x->lt($y, $c, 0);        # method call, all params given
   $c = $x->lt($y);          # method call
   $x->inplace->lt($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. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.

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

the binary <= (less equal) operation

   $c = $x <= $y;               # overloaded call
   $c = PDL::le($x, $y);     # explicit call with default swap of 0
   $c = PDL::le($x, $y, 0);  # explicit call with explicit swap of 0
   $c = PDL::le($x, $y, 1);  # explicit call with trailing 1 to swap args
   PDL::le($x, $y, $c, 1);   # all params given
   $x->le($y, $c, 0);        # method call, all params given
   $c = $x->le($y);          # method call
   $x->inplace->le($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. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.

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

the binary >= (greater equal) operation

   $c = $x >= $y;               # overloaded call
   $c = PDL::ge($x, $y);     # explicit call with default swap of 0
   $c = PDL::ge($x, $y, 0);  # explicit call with explicit swap of 0
   $c = PDL::ge($x, $y, 1);  # explicit call with trailing 1 to swap args
   PDL::ge($x, $y, $c, 1);   # all params given
   $x->ge($y, $c, 0);        # method call, all params given
   $c = $x->ge($y);          # method call
   $x->inplace->ge($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. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.

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

binary equal to operation ("==")

   $c = $x == $y;               # overloaded call
   $c = PDL::eq($x, $y);     # explicit call with default swap of 0
   $c = PDL::eq($x, $y, 0);  # explicit call with explicit swap of 0
   $c = PDL::eq($x, $y, 1);  # explicit call with trailing 1 to swap args
   PDL::eq($x, $y, $c, 1);   # all params given
   $x->eq($y, $c, 0);        # method call, all params given
   $c = $x->eq($y);          # method call
   $x->inplace->eq($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. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.

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

binary not equal to operation ("!=")

   $c = $x != $y;               # overloaded call
   $c = PDL::ne($x, $y);     # explicit call with default swap of 0
   $c = PDL::ne($x, $y, 0);  # explicit call with explicit swap of 0
   $c = PDL::ne($x, $y, 1);  # explicit call with trailing 1 to swap args
   PDL::ne($x, $y, $c, 1);   # all params given
   $x->ne($y, $c, 0);        # method call, all params given
   $c = $x->ne($y);          # method call
   $x->inplace->ne($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. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.

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

leftshift $a by $b

   $c = $x << $y;               # overloaded call
   $c = PDL::shiftleft($x, $y);     # explicit call with default swap of 0
   $c = PDL::shiftleft($x, $y, 0);  # explicit call with explicit swap of 0
   $c = PDL::shiftleft($x, $y, 1);  # explicit call with trailing 1 to swap args
   PDL::shiftleft($x, $y, $c, 1);   # all params given
   $x->shiftleft($y, $c, 0);        # method call, all params given
   $c = $x->shiftleft($y);          # method call
   $x->inplace->shiftleft($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. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.

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

rightshift $a by $b

   $c = $x >> $y;               # overloaded call
   $c = PDL::shiftright($x, $y);     # explicit call with default swap of 0
   $c = PDL::shiftright($x, $y, 0);  # explicit call with explicit swap of 0
   $c = PDL::shiftright($x, $y, 1);  # explicit call with trailing 1 to swap args
   PDL::shiftright($x, $y, $c, 1);   # all params given
   $x->shiftright($y, $c, 0);        # method call, all params given
   $c = $x->shiftright($y);          # method call
   $x->inplace->shiftright($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. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.

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

binary or of two ndarrays

   $c = $x | $y;               # overloaded call
   $c = PDL::or2($x, $y);     # explicit call with default swap of 0
   $c = PDL::or2($x, $y, 0);  # explicit call with explicit swap of 0
   $c = PDL::or2($x, $y, 1);  # explicit call with trailing 1 to swap args
   PDL::or2($x, $y, $c, 1);   # all params given
   $x->or2($y, $c, 0);        # method call, all params given
   $c = $x->or2($y);          # method call
   $x->inplace->or2($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. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.

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

binary and of two ndarrays

   $c = $x & $y;               # overloaded call
   $c = PDL::and2($x, $y);     # explicit call with default swap of 0
   $c = PDL::and2($x, $y, 0);  # explicit call with explicit swap of 0
   $c = PDL::and2($x, $y, 1);  # explicit call with trailing 1 to swap args
   PDL::and2($x, $y, $c, 1);   # all params given
   $x->and2($y, $c, 0);        # method call, all params given
   $c = $x->and2($y);          # method call
   $x->inplace->and2($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. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.

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

binary exclusive or of two ndarrays

   $c = $x ^ $y;               # overloaded call
   $c = PDL::xor($x, $y);     # explicit call with default swap of 0
   $c = PDL::xor($x, $y, 0);  # explicit call with explicit swap of 0
   $c = PDL::xor($x, $y, 1);  # explicit call with trailing 1 to swap args
   PDL::xor($x, $y, $c, 1);   # all params given
   $x->xor($y, $c, 0);        # method call, all params given
   $c = $x->xor($y);          # method call
   $x->inplace->xor($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. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.

  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);    # explicit call with default swap of 0
   $c = $x->power($y, 1); # explicit call with trailing 1 to swap args
   $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. As of 2.065, when calling this function explicitly you can omit the third argument (see first example), or supply it (see second one).

power 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.

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

elementwise "atan2" of two ndarrays

   $c = $x->atan2($y);    # explicit call with default swap of 0
   $c = $x->atan2($y, 1); # explicit call with trailing 1 to swap args
   $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. As of 2.065, when calling this function explicitly you can omit the third argument (see first example), or supply it (see second one).

atan2 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.

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

elementwise "modulo" operation

   $c = $x->modulo($y);    # explicit call with default swap of 0
   $c = $x->modulo($y, 1); # explicit call with trailing 1 to swap args
   $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. As of 2.065, when calling this function explicitly you can omit the third argument (see first example), or supply it (see second one).

modulo 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.

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

elementwise "<=>" operation

   $c = $x->spaceship($y);    # explicit call with default swap of 0
   $c = $x->spaceship($y, 1); # explicit call with trailing 1 to swap args
   $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. As of 2.065, when calling this function explicitly you can omit the third argument (see first example), or supply it (see second one).

spaceship 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.

  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. Flows data back & forth.

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. Flows data back & forth.

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

assgn 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.

  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(); longlong b(); [o] ans())

raise ndarray $a to integer power $b

   $c = $x->ipow($y);     # as method
   $c = ipow $x, $y;
   $x->inplace->ipow($y);  # modify $x inplace

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

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

Returns the square of the absolute value of a number.

abs2 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.

  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).