.TH MAKECPT l "1 Mar 2002"
.SH NAME
makecpt \- Make GMT color palette tables
.SH SYNOPSIS
\fBmakecpt\fP [ \fB\-C\fP\fItable\fP ]
[ \fB\-I\fP ] [ \fB\-T\fP\fIz0/z1/dz\fP | \fB\-T\fP\fIztable\fP] [ \fB\-V\fP ] [ \fB\-Z\fP ]
.SH DESCRIPTION
\fBmakecpt\fP is a utility that will help you make color palette tables (cpt files). You define
an equidistant set of contour intervals or pass your own z-table, and create a new cpt file based on
an existing master cpt file. The resulting cpt file can be reversed relative
to the master cpt, and can be made continuous or discrete.
.SH OPTIONS
.TP
.B \-C
Selects the master color table \fItable\fP to use in the interpolation.
Choose among the built-in tables (type \fBmakecpt\fP to see the list) or
give the name of an existing cptfile [Default gives a rainbow cpt file].
.TP
.B \-I
Reverses the sense of color progression in the master cptfile.
.TP
.B \-T
Defines the range of the new cptfile by giving the lowest and highest z-value
and the interval. Alternatively, give the name of a ASCII file that has one
z-value per record. If not given, the existing range in the master cptfile
will be used intact.
.TP
.B \-V
Selects verbose mode, which will send progress reports to stderr [Default runs "silently"].
.TP
.B \-Z
Creates a continuous cpt file [Default is discontinuous, i.e. constant colors
for each interval].
.SH EXAMPLES
To make a cpt file with z-values from -200 to 200, with discrete color changes every
25, and using a polar blue-white-red colortable, try
.br
.sp
makecpt \fB\-C\fP\fIpolar\fP \fB\-T\fP-200/200/25 > colors.cpt
.br
.sp
To make an equidistant cpt file from z = -2 to 6, in steps of 1, using
continuous default rainbow colors, try
.br
.sp
makecpt \fB\-T\fP-2/6/1 \fB\-Z\fP > rainbow.cpt
.br
.sp
To make a GEBCO look-alike cpt file for bathymetry, try
.br
.sp
makecpt \fB\-C\fPgebco > my_gebco.cpt
.SH BUGS
Since \fBmakecpt\fP will also interpolate from any existing .cpt file you
may have in your directory, you cannot use one of the listed cpt names
as an output filename; hence the my_gebco.cpt in the example.
.SH "SEE ALSO"
.IR gmt (l),
.IR grd2cpt (l)