how to make a new color table in GMT

Sonia Bargn · 10-15-2015, 12:50 PM

Hi everybody
hope everything is just safe and sound.
there are some color tables (cpt files) in GMT and "makecpt" command helps to use these cpt files. but I want to create a new cpt file with my own arbitrary color scale.
how can I do that?
Many thanks.

TB0ne · 10-15-2015, 03:14 PM

Quote:

Originally Posted by Sonia Bargn

Hi everybody
hope everything is just safe and sound.
how can I create a new cpt file in GMT? I'm expected to create a new color scale.

Many thanks.

We also expect you to read the LQ Rules about posting the same question multiple times, and the "Question Guidelines". Had you even tried to look this up, the VERY FIRST HIT in Google for "how can I create a new cpt file in gmt" is:
http://gmt.soest.hawaii.edu/doc/5.1.0/makecpt.html

...amazingly, from the GMT site.

Sonia Bargn · 10-15-2015, 04:10 PM

Dear TB0ne
I mean a new table in "makecpt" command.
How can I create a new table?

ardvark71 · 10-15-2015, 04:21 PM

Quote:

Originally Posted by Sonia Bargn

I'm expected to create a new color scale.

Hi...

I know nothing about this program or how one would do this but for the benefit of those who might be able to help, what color scale or range are you wanting to produce?

Regards...

John VV · 10-15-2015, 04:36 PM

only a very FEW of us know what Generic Mapping Tools ( GMT ) are and even LESS know what a color pallet is and what it is used for
( GDAL and ISIS3 are the tools i use most and Qgis)

you really need to be specific
and have you even bothered to READ!!! the "--help" page??????
http://gmt.soest.hawaii.edu/doc/5.1.0/makecpt.html
or

Code:

makecpt --help

-----/* and read */ ----

man makecpt

Sonia Bargn · 10-16-2015, 01:44 AM

Dear ardvark71
colors can be based on RGB codes (red,green,blue: for example black defines by 0/0/0 and white is 255/255/255. other colors is a range between these codes) in this program, I want a color scale which shows white for zero and then,blue, green, yellow, red till 50. unfortunately this color scale in not in program's default. the point is, color scale must be continuous. cpt file is a file which defines this RGB codes. I don't know how can I make my own continuous color scale.

Quote:

Originally Posted by ardvark71

Hi...

I know nothing about this program or how one would do this but for the benefit of those who might be able to help, what color scale or range are you wanting to produce?

Regards...

Sonia Bargn · 10-16-2015, 01:48 AM

Dear John VV
I've read the help page, but it states how you can use from program's color table, I wanna make a new color table.

TB0ne · 10-16-2015, 08:44 AM

Quote:

Originally Posted by Sonia Bargn

Dear John VV
I've read the help page, but it states how you can use from program's color table, I wanna make a new color table.

If you "wanna" make a new table, then READ the page you were given in the first reply. From the top of that page:

Quote:

Originally Posted by makecpt Page

makecpt 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. For color tables beyond the standard GMT offerings, visit cpt-city: http://soliton.vm.bytemark.co.uk/pub/cpt-city/.

Read the instructions and follow them.

Sonia Bargn · 10-16-2015, 09:54 AM

I don't know how to define an equidistant set of intervals that result a continuous color scale, can u do a great favor and help me?

TB0ne · 10-16-2015, 10:32 AM

Quote:

Originally Posted by Sonia Bargn

I don't know how to define an equidistant set of intervals that result a continuous color scale, can u do a great favor and help me?

Again, read the LQ Rules...text-speak isn't good. And we will always be happy to HELP you...but we will NOT write things for you.

Show us what effort you have put forth, and tell us where you're stuck. Otherwise, you're just continuing to ask for a handout. You didn't appear to have done any research on how to do this (re: first hit in Google had the answer), and now you're asking us to write things for you. ESPECIALLY since you've been asking about GMT for about a year now, AND given the fact that there is a link on the web page you were handed that has SAMPLE CPT files already there for you to view.

Sorry, but no.

Tinkster · 10-19-2015, 03:14 PM

Please post your thread in only one forum. Posting a single thread in the most relevant forum will make it easier for members to help you and will keep the discussion in one place. This thread is being closed because it is a duplicate.

http://www.linuxquestions.org/questi...0/#post5434895