Provided by: pdl_2.020-3_amd64 
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 $x, $y, 0; # explicit call with trailing 0
$c = $x + $y; # overloaded call
$x->inplace->plus($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 "+" 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 $x, $y, 0; # explicit call with trailing 0
$c = $x * $y; # overloaded call
$x->inplace->mult($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 "*" 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 $x, $y, 0; # explicit call with trailing 0
$c = $x - $y; # overloaded call
$x->inplace->minus($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 "-" 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 $x, $y, 0; # explicit call with trailing 0
$c = $x / $y; # overloaded call
$x->inplace->divide($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 "/" 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 $x, $y, 0; # explicit call with trailing 0
$c = $x > $y; # overloaded call
$x->inplace->gt($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 ">" 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 $x, $y, 0; # explicit call with trailing 0
$c = $x < $y; # overloaded call
$x->inplace->lt($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 "<" 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 $x, $y, 0; # explicit call with trailing 0
$c = $x <= $y; # overloaded call
$x->inplace->le($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 "<=" 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 $x, $y, 0; # explicit call with trailing 0
$c = $x >= $y; # overloaded call
$x->inplace->ge($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 ">=" 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 $x, $y, 0; # explicit call with trailing 0
$c = $x == $y; # overloaded call
$x->inplace->eq($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 "==" 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 $x, $y, 0; # explicit call with trailing 0
$c = $x != $y; # overloaded call
$x->inplace->ne($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 "!=" 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 $x, $y, 0; # explicit call with trailing 0
$c = $x << $y; # overloaded call
$x->inplace->shiftleft($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 "<<" 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 $x, $y, 0; # explicit call with trailing 0
$c = $x >> $y; # overloaded call
$x->inplace->shiftright($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 ">>" 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 $x, $y, 0; # explicit call with trailing 0
$c = $x | $y; # overloaded call
$x->inplace->or2($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 "|" 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 $x, $y, 0; # explicit call with trailing 0
$c = $x & $y; # overloaded call
$x->inplace->and2($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 "&" 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 $x, $y, 0; # explicit call with trailing 0
$c = $x ^ $y; # overloaded call
$x->inplace->xor($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 "^" 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
$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 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 = $x->power($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 piddles is unknown.
atan2
Signature: (a(); b(); [o]c(); int swap)
elementwise "atan2" of two piddles
$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 piddles 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 piddles 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 piddles 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 piddles if the flag is set for
any of the input piddles.
abs
Signature: (a(); [o]b())
elementwise absolute value
$y = abs $x;
$x->inplace->abs; # modify $x inplace
It can be made to work inplace with the "$x->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
$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 piddles if the flag is set for
any of the input piddles.
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 piddles if the flag is set for
any of the input piddles.
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 piddles if the flag is set for
any of the input piddles.
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 piddles if the flag is set for
any of the input piddles.
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 piddles if the flag is set for
any of the input piddles.
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 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
If "a" is a child piddle (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.
ipow
Signature: (a(); b(); [o] ans())
raise piddle $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 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).