cptcont man page

cptcont — create a continuous GMT colour palette table (cpt) file based on the colours of a non-continuous cpt file.


cptcont [-h] [-m] [-o file] [-p percent] [-v] [-V] [file]


The cptcont program converts a (possibly) discontinuous colour palette in the input to a continuous palette in the output. This is achieved by replacing the endpoints of segments at which a discontinuity occurs by their mean colour.

The program will read from stdin if a file is not specified as the final argument, and 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.

-m, --midpoint

Split each input segment into two output segments with the colour at the common point being the colour of the original segment. This gives a more faithful conversion of gradients with "corners", such as diverging gradients, albeit at the cost of larger files.

-o, --output file

Write the output to file, rather than stdout.

-p, --partial percentage

The endpoints are moved the specified pecentage towards the mean colour, so that a value of 100 (the default) moves the endpoints to the mean colour, 50 moves them half-way there, and so on.

Negative values and values greater than 100 are permitted.

-v, --verbose

Verbose operation.

-V, --version

Version information.


Create an almost-continuous table:

cptcont -v -p 66 -o new.cpt old.cpt


J.J. Green

See Also


Referenced By


2 Aug 2016 CPTUTILS User commands