GRASS and GMT

2008-03-13T01:58:33Z

⚠️Gordonke: /* Importing from GMT */

= GMT (The Generic Mapping Tools) =

GMT (Generic Mapping Tools) is a Free software package for creating publication quality cartography.

GMT homepage: http://gmt.soest.hawaii.edu

== Importing from GMT ==

* Reformat the GMT grid to the old format using 'grdreformat in.grd out.grd=bf' then use r.in.bin with the -h flag 'r.in.bin -hf in=out.grd out=raster', or try the [http://www.gdal.org/frmt_various.html#GMT netCDF GDAL driver] with r.in.gdal.

* Import GMT style .cpt color table files with the r.cpt2grass script on the [[GRASS_AddOns|Add-ons]] page.
:For a large collection of GMT .cpt files see http://sview01.wiredworkplace.net/pub/cpt-city/

== Exporting GRASS maps to GMT ==

* Overview: http://169.237.35.250/~dylan/grass_user_group/#GMT_and_GRASS-overview
<BR>(Supplied by the GRASS Users Group of Davis, California)

Currently there are several *.out.GMT permutations on the [[GRASS_AddOns|Add-ons]] page, in several different languages (bash, python, etc.), and each of which with relative pros/cons. An effort to unify these approaches would save much of the current difficulties in moving complex raster+vector data into a GMT-friendly format. A simple road map toward this goal is outlined:

=== Proper conversion of GRASS raster color data into GMT compatible CPT files ===
David Finlayson's [http://david.p.finlayson.googlepages.com/gisscripts r.out.gmt.py] does a nice job of this. Once we decide on an optimal language to implement the routines in this may need translation.

=== Proper conversion of GRASS raster data to GMT compatible binary grids ===
A combination of r.out.bin | xyz2grd can accomplish this. Several attempts at generalizing this procedure have been proposed: [http://david.p.finlayson.googlepages.com/gisscripts r.out.gmt.py], [http://bambi.otago.ac.nz/hamish/grass/r.out.gmt r.out.gmt] (Hamish and Dylan), [http://169.237.35.250/~dylan/grass_user_group/r.out.gmt.sh r.out.gmt.sh] (Dylan, based Hamish's work).

=== Proper conversion of GRASS vector data to GMT compatible ascii files ===
There is currently an effort (with some funding!), see some of the chatter on the GRASS and GMT mailing lists:
[http://grass.itc.it/pipermail/grassuser/2006-April/033659.html GRASS-list]
[http://www.nabble.com/Ideas-needed-regarding-OGR-reformatter-for-GMT-vector-(point-multiline)-files.-t2605255.html GMT-help]

=== Automatic conversion of symbology data stored in a gis.m or QGIS saved state to GMT options ===

Ideas expressed on various mailing list, haven't seem much since. It ''should'' be a relatively simple excercise in XML parsing to convert symbology stored in a QGIS project file into something that GMT can use.

=== General approach ===
Since GMT relies on a sequence of specialized programs to "build-up" a postscript file, some thought must be put into how the conversion should take place. As usual, form should follow function- maximum flexibility, robustness, and accuracy being primary objectives. However, a simple means of creating high quality 2D maps would be a tremendous (I think) addition to the GRASS toolset. Especially since this is something frequently cited by critics. --[[User:DylanBeaudette|DylanBeaudette]] 02:47, 10 December 2006 (CET)

1. should we continue down the well troden path of single-use, highly efficient programs for the various conversion steps: i.e v.out.GMT, r.out.GMT, etc.?

2. should there be a unified approach to the process: something akin to ps.map - ''GMT.map'' ?

= Tutorials =
* [http://netgis.geo.uw.edu.pl/srtm/ Dane DEM uzyskane z radarowej misji promu kosmicznego - SRTM-3]: Tutorial in Polish

GRASS-Wiki - User contributions [en]

GRASS and GMT