Trix & Graphix

GMT: a very brief introduction

GMT is a set of tools (command line programs) to manipulating geographic data sets, and in particular to create maps. This set of tools are a great example of the philosofy that should follow all the Unix programs: very light, fast and each tools does just one thing, but does it well. Here there are some examples of the kind of things that you can get with these tools. Maybe the bigger problem with GMT is the complexity when using it, the thousand of options and its dark syntax. In this blog I'll try to post some tips & tricks I have found out up to now... I still learn new things every day.


The general way of plotting a map with GMT is to use several tools sequentially. Each tool adds a new detail in the final result. For example, the coastlines are added with pscoast, shadings are added with grdimage, some symbols are included later with psxy and so on. When a command is called, the output of GMT is EPS code through the standard output of the terminal. Thus, you have to redirect the output after each call to GMT to the same EPF file (which is, by the way, an ASCII file). As you can understand, in order to work sucessfully with GMT, bash scripting is mandatory. Otherwise, you will become mad after just 10 minutes using it.

The syntax is nevertheless quite complex. In the next posts I'll explain some details about it. Anyway, the best place to learn about GMT is, as could be expected in a Unix program, the man pages. Just as a general comment, the syntax is something like:
command -Flag1Options -Flag2Options > file.eps
where command is one of the many GMT tools. Flag1 and Flag2 can be -D, -O, -B,... there are tens of flags which deppend on the exact tool. Finally, Options are the many options you can use for each flag. It's important to note that there is no space between the flag and the option. For example you have to use -Aa0tf10 instead of -A a0 t f10.

Well, I know, it's very complicated. I'll put some examples in the next posts...

4 Comments:

e3mar Dora said...

شركة تنظيف كنب بخميس مشيط
شركة تنظيف سجاد بخميس مشيط
شركة كشف تسربات المياه بخميس مشيط
شركة تخزين عفش بخميس مشيط
شركة عزل خزانات بخميس مشيط
شركة كشف تسربات المياه بالرياض
شركة غسيل خزانات بخميس مشيط
شركة صيانة مسابح بخميس مشيط
شركة تنظيف الاثاث بخميس مشيط
شركة جلي بلاط بخميس مشيط
شركة تنظيف شقق بخميس مشيط
شركة نقل عفش بخميس مشيط
شركة تنظيف موكيت بخميس مشيط
شركة تنظيف مجالس بخميس مشيط

e3mar Dora said...

شركة تنظيف مسابح بخميس مشيط
شركة تنظيف منازل بخميس مشيط

شركات مكافحة النمل الابيض بالرياض
شركة مكافحة حشرات بالرياض
شركة رش مبيدات بالرياض
شركة مكافحة الفئران بخميس مشيط
شركة مكافحة حشرات بخميس مشيط
شركة تسليك مجاري بالرياض
شركة رش مبيدات بخميس مشيط


شركة عزل اسطح بخميس مشيط

شركة تنظيف فلل بخميس مشيط

e3mar Dora said...

شركة رش الدفان بخميس مشيط
شركة مكافحة النمل الابيض بخميس مشيط
شركة مكافحة البق بخميس مشيط
شركة مكافحة الصراصير بخميس مشيط

هنا
شركة تسليك مجارى بخميس مشيط
شركة تنظيف خزانات بخميس مشيط

Ana Esraa said...

https://decor-ksa.com/
http://caravank.com/factory/
http://caravank.com/for-sale-in-riyadh/
http://caravank.com/withdrawn-for-sale/