Colours are the deeds of light; its deeds and sufferings: thus considered we may expect from them some explanation respecting light itself.
DESCRIPTION
The cptclip utility extracts a sub-table from
a cpt format file. The arguments to the mandatory --range
option,
min
/max
,
are interpreted as the (z) limits of the output unless the --segments
switch is specified, in which case they are the segment numbers.
If the input has a hinge and the selected clipping range does not include that hinge, then it will be removed in the output.
The program will read from stdin
if a file is not specified as
the final argument, and write to stdout
if the --output
option is not specified.
Note that some of the functionality of this program is included in recent versions of the GMT program makecpt (1) .
OPTIONS
--backtrace-file
path
-
Specify a file to which to write a formatted backtrace. The file will only be created if there is a backtrace created, typically when an error occurs.
--backtrace-format
format
-
Specify the
format
of the backtrace written to the files specified by--backtrace-file
, one ofplain
,xml
orjson
. -h
,--help
-
Brief help.
--hinge
value
-
Specify the z-
value
of the hinge in the cpt file. If there is no hinge directive (i.e., aSOFT_HINGE
orHARD_HINGE
) in the input, then this option has no effect.When normalising (with the
--z-normalise
option), this gives the z-value in the input which is mapped to zero. That z-value must be one of the stops in the input.When denormalising (with the
--z-denormalise
option), this gives the value in the output to which zero in the input is mapped. This option can be viewed as the counterpart to the+h
appended to thevalue
-C
option for the makecpt (1) . --hinge-active
-
If the input cpt has a
SOFT_HINGE
directive, then activate that hinge (resulting in independent scaling of the two halves of the gradient either side of the hinge).If the input does not have such a directive, then this option has no effect.
-o
,--output
path
-
Write the output to
path
, rather thanstdout
. -R
,--range
min
/max
-
The (z) range of the output, or the segments if the
--segments
switch is also given. -s
,--segments
-
The
min
andmax
arguments of the--range
switch are interpreted as the segment numbers (starting at one). -v
,--verbose
-
Verbose operation.
-V
,--version
-
Version information.
-z
,--z-normalise
-
Normalise the z-values in the cpt output into the range 0/1 (or to -1/1 if a hinge is present) and add a
RANGE
directive if not present in the input. This is the form used in GMT master files.This option requires that output cpt version is at least 5.
-Z
,--z-denormalise
-
Set the z-values in the cpt output into the range given by the
RANGE
directive, and remove that directive. If there is noRANGE
then this option does nothing. -4
,--gmt4
-
Use GMT 4 conventions when writing the cpt output: the colour-model code is uppercase, and the colours are separated by spaces.
This is incompatible with the
-5
and-6
options of course.At present this option is the default, but that will change at some point. So specify this option if your use of the output depends on the GMT 4 layout (consumed by a custom parser, for example).
-5
,--gmt5
-
Use GMT 5 conventions when writing the cpt output: the colour-model code is lowercase, and the colours are separated by a solidus for RGB, CMYK, by a dash for HSV.
This is incompatible with the
-4
and-6
options of course. -6
,--gmt6
-
As the
-5
option, but allows theHARD_HINGE
andSOFT_HINGE
directives in place of the explicitHINGE =
directive.This is incompatible with the
-4
and-5
options of course.