UDUNITSPerl(1) UNIDATA UTILITIES UDUNITSPerl(1)NAMEudunitsperl - perl extension for UDUNITS
SYNOPSIS
use UDUNITS;
UDUNITS::init($path)
$unit = UDUNITS::new()
$unit = UDUNITS::scan($spec)
$unit2 = UDUNITS::dup($unit)
$unit->hasorigin()
$unit->istime()
$unit->clear()
$unit->invert()
$unit->shift($amount)
$unit->scale($factor)
$unit->raise($power)
$unit->multiply($unit2)
$unit->divide($unit2)
$unit->convert($unit2, $slope, $intercept)
$unit2 = $unit->dup()
$spec = $unit->print()
$timeunit->valtocal($value, $year, $month, $day, $hour, $minute, $second)
$value = $timeunit->caltoval($year, $month, $day, $hour, $minute, $second)
UDUNITS::term()DESCRIPTION
UDUNITSPerl is a port of the udunits(3) library into a native Perl 5
extension.
PACKAGE FUNCTIONS
The functions in the UDUNITS package should be invoked by use of the
UDUNITS:: prefix (e.g. UDUNITS::scan() invokes the scan() function).
init($path)
Initializes the UDUNITS module. File $path is the units database
to be read. If $path is the empty string, then the default data‐
base is read. The default database is determined at the time the
UDUNITS package is installed.
new()
Returns a trivial unit object. A trivial unit object is dimension‐
less and has the value 1.
scan($spec)
Returns a unit object determined by the string $spec or an unde‐
fined perl scalar if the UDUNITS module hasn't been initialized or
the units specification is invalid.
dup($unit)
Returns a duplicate of unit object $unit. This action is identical
to invoking the dup() member function of a unit object (e.g.
$unit->dup()).
term()
Terminates use of the UDUNITS module. Frees allocated resources.
MEMBER FUNCTIONS
Every unit object created by one of the above functions has a set of
method functions. A member function is invoked by using the unit ob‐
ject as a reference (e.g. $unit->invert() invokes the invert() member
function of unit object $unit).
hasorigin()
Returns true if the unit has an origin (possibly set via the
shift() member function) and false otherwise.
istime()
Returns true if the unit is a pure unit of time (e.g. "sec‐
onds").
clear()
Clears the unit object by setting it to the trivial unit object.
invert()
Inverts the unit object (e.g. "seconds" becomes "1/seconds").
shift($amount)
Shifts the origin of the unit object by the amount $amount.
scale($factor)
Scales the unit object by the amount $factor.
raise($power)
Raises the unit object by the power $power.
multiply($unit2)
Multiplies the unit object by the unit $unit2.
divide($unit2)
Divides the unit object by the unit $unit2.
convert($unit2,$slope,$intercept)
Computes the slope and intercept necessary to convert values in
units of the unit object into values in units of unit2. Returns
0 on success, UDUNITS::ENOINIT if the units module hasn't been
initialized, and UDUNITS::ECONVERT if the unit objects are not
convertable.
dup() Returns a duplicate of unit object. This action is identical to
invoking the UDUNITS::dup($unit) package function.
print()
Returns the canonical string specification of the unit object
(e.g. "kilogram meter second-2").
valtocal($value, $year, $month, $day, $hour, $minute, $second)
Breaks down the value $value in units of the unit object into
UTC calendar time. Returns 0 on success, UDUNITS::EINVALID if
the unit object is not a unit of time, and UDUNITS::ENOINIT the
units module hasn't been initialized. The returned $second ar‐
gument is floating-point.
caltoval($year, $month, $day, $hour, $minute, $second)
Returns the value in units of the unit object that corresponds
to the given UTC calendar time or a perl undefined scalar if the
units module hasn't been initialized or the unit object is not a
unit of time. If defined, then the returned value is floating-
point. The $second argument may be floating-point.
In addition to the above functions, most C macro constants that are de‐
fined in the UDUNITS header file udunits.h are also available to a perl
script by dropping any `UT_' substring and using the UDUNITS:: prefix,
e.g. UDUNITS::EINVALID.
SEE ALSOperl(1), udunits(3)Printed: 124-4-28 $Date: 2003/04/29 15:57:37 $ UDUNITSPerl(1)
