Grid file from a txt file

Q&A
1

How to make grdfile from txt file1?

2

That depends. You need to give us more information. We are not mind readers.

3

I want to make bougar gravity map I have data in long lat and data.

Complete-Bouguer-anomaly-map-in-mGal-of-the-southern-Indian-shield-is-based-on-more (1)
Complete-Bouguer-anomaly-map-in-mGal-of-the-southern-Indian-shield-is-based-on-more (1)640×557 95.6 KB

I want to make this kind of map.
I have data in
Screenshot (221)
Screenshot (221)1920×1080 104 KB

psbasemap -JM10c -R65/100/5/40 -B5/5WSen -K -Y4 >map.ps
gmt txt2grd -i2,1,3 -R65/100/5/40 -J -O -K -fg -Goutput.gravity.txt

Now, how should I proceed.

4

The values in gravity.xyz looks gridded to me.

Then you should figure out what the x- and y-increment is, and the region that the grid covers and use xyz2grd;

gmt xyz2grd gravity.xyz -Ixinc/yinc -Rw/e/s/n -Goutput.gravity.nc

Then you should get a gridfile that gmt can use. Next would be to plot it (and mask areas with no data).

5

Tip: gmt info gravity.xyz to get the extent.

Increment you have to eyeball the textfile. I dont know of a way to check this.

6

gmt psbasemap -R65/100/5/40 -JM4i -B5/5WSen -K -Y4 >map.ps
gmt xyz2grd gravity.xyz -Ix1/y1 -R65/100/5/40 -Goutput.gravity.nc
grdimage gravity_nn.nc -R -J -O -K -Cfinal.cpt >>map.ps
gmt pscoast -R -J -O -K -Na >>map.ps
psscale -D/-2/12/0.5h -B10::/:mgal: -Cfinal.cpt -O -K >> map.ps
#pscolorbar -Dx1i/7i+w4i/0.5i+h -Cfinal.cpt -Ba -B+tcontinuous -I0.5

This is my script but I am not able to proceed.

7

Your xyz2grd command should be

gmt xyz2grd gravity.xyz -I<number>/<number> -R65/100/5/40 -Goutput.gravity.nc

I dont know what the increment in the grid is (or even if it is a grid at all), but something like

gmt xyz2grd gravity.xyz -I0.0167/0.0167 -R65/100/5/40 -Goutput.gravity.nc

may work.

Good progress!

10

  • Please 1: Don’t post screen-captures. Copy past the text and wrapp it pairs of triple back ticks (```) for formatting

  • Please 2: Pay attention to the error messages. If your system is saying xyz2grd ... no such file (gravity.xyz) you will advance nothing by ignoring this (and others) error messages.