cptcat — concatenate GMT colour palette tables.


cptcat [-h ] [-o file ] [-v ] [-V ] file...


The cptcat utility concatenates two or more GMT colour palette table (cpt) files. The mandatory file arguments specify the input files which may be specified in any order. However, when sorted, the maximum (z-value) of the lower file should equal the minimum of the upper file; files can be modified with the makecpt(1) utility to be in this form.

The background colour will be taken from that of the lower (or lowest) file, and the forground from that of the upper.

The program will write to stdout if the -o option is not specified.


--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 of plain, xml or json.

-h, --help

Brief help.

-o, --output file

Write the output to file, rather than stdout.

-v, --verbose

Verbose operation.

-V, --version

Version information.


Create a cpt-file topobath.cpt from topo.cpt and bath.cpt

cptcat -v -o topobath.cpt topo.cpt bath.cpt


J.J. Green


GMT(1), makecpt(1).