NAME¶
PDL::Graphics::LUT - provides access to a number of look-up tables
SYNOPSIS¶
use PDL::Graphics::PGPLOT;
use PDL::Graphics::LUT;
# what tables are available
my @tables = lut_names();
# get the reversed colour table 'smooth',
# with the gamma intensity ramp
my ( $l, $r, $g, $b ) = lut_data( 'smooth', 1, 'gamma' );
# use the table idl5 in ctab
ctab( lut_data('idl5') );
DESCRIPTION¶
PDL::Graphics::LUT contains a number of colour look-up tables (in rgb format)
and intensity ramps, and provides routines to access this data. The format of
the data is suitable for use by ctab.
Unlike the initial release of the package, the data tables are now stored within
the PDL distribution as FITS files (see $tabledir and $rampdir), rather than
in the module itself. Changes to these directories will be picked up on the
next call to one of the package functions.
FUNCTIONS¶
lut_names()¶
Return, as a list, the names of the available colour tables.
@tables = lut_names();
lut_ramps()¶
Return, as a list, the names of the available intensity ramps.
@ramps = lut_ramps();
lut_data()¶
Load in the requested colour table and intensity ramp.
( $l, $r, $g, $b ) = lut_data( $table, [ $reverse, [ $ramp ] ] );
Returns the levels and r, g, b components of the colour table $table. If
$reverse is 1 (defaults to
0 if not supplied), then the r, g, and b
components are reversed before being returned. If not supplied, $ramp defaults
to
"ramp" (this is a linear intensity ramp).
The returned values are piddles containing values in the range 0 to 1 inclusive,
and are floats.
VARIABLES¶
$tabledir¶
The directory in which the colour tables (in rgb format) are stored.
$rampdir¶
The directory in which the intensity ramps are stored.
$suffix¶
The suffix for the data files in $tabledir and $rampdir.
The colour tables were taken from the STARLINK GAIA package, and are provided
under the GNU copyleft. See
http://star-www.rl.ac.uk/ and
http://star-www.dur.ac.uk/~pdraper/ for more details.
AUTHOR¶
Doug Burke (djburke@cpan.org), with thanks to Peter Draper/STARLINK for
providing the colour-table data, and Christian Soeller and Karl Glazebrook for
their help.
All rights reserved. There is no warranty. You are allowed to redistribute this
software / documentation under certain conditions. For details, see the file
COPYING in the PDL distribution. If this file is separated from the PDL
distribution, the copyright notice should be included in the file.