I am not sure if I am missing something in my .grd creation but after running xyz2grd I am getting different values (min/max) from my original data. I was not expecting any kind of interpolation at this step.
So, I checked my .txt file before and I have a min max of -1330.21 to 5.526101
Its a global .txt file spaced by 2x2 degree from 0 top 358 and -90 to 88
Well, you certainly want to use -R0/360/-90/90 unless you actually have no data in those two strips. No interpolation takes place, but if many points land on the same node there will be averaging. Finally, given your issue with -R you may also consider what is your registration (pixel vs gridline) and if you need to add -r.
Hi Paul, it’s such a pleasure got an answer from you.
So, I tried using the global region and I got the same results.
When I just add -r in the end of my code I got something more consistent:
v_min: -1074.24755859 v_max: 4.99047279358 name: z almost 1000 difference in the v_min
But seems like my .grd file its not covering the whole globe anymore.
About my registration I am not 100% sure about it but I will do some combination (grdmath) using different grid for the same area. I think gridline would be better in this case.
If I just moving xyz to grd, no interpolation, why I am not getting same min values?
If your min value is truly -1330 and grid node minimum is -1074 it means values are averaged because more than one value fall on the same node. Perhaps you could post your data set here - hard to guess further.