Re: GRDGRADIENT
Paul Wessel <[email protected]>
| Newsgroups | gmane.comp.gis.gmt.user |
|---|---|
| Message-ID | <[email protected]> |
You are entering latitudes as longitudes and vice versa in the -R option. On Feb 20, 2014, at 12:57 PM, Mr Abhash Kumar <[email protected]> wrote: > Hi, > I am trying use grdcut around the center latitude/longitude of -15.5/-71.5 as below: > > grdcut slabsurf2.grd -Gslabcut.grd -R-15.6/-15.4/-71.6/-71.4 -V > > But I am getting the following error: > grdcut: Subset exceeds data domain! > > I run grdinfo to check the range of my slab grid file: > grdinfo slabsurf2.grd > > slabsurf2.grd: x_min: -82 x_max: -66 x_inc: 0.0744186046512 name: x nx: 216 > slabsurf2.grd: y_min: -20 y_max: -9 y_inc: 0.0718954248366 name: y ny: 154 > > I couldn't understand why the grdcut is giving this error. I would be grateful for any suggestions. > > Thanks > Abhash kumar > From: World-Wide GMT Usage and Help Mailing List <[email protected]> on behalf of Paul Wessel <[email protected]> > Sent: Thursday, February 20, 2014 5:12 PM > To: [email protected] > Subject: Re: [GMT-HELP] GRDGRADIENT > > I cannot tell if anything is wrong here. You would have to show based on your data that these strikes are wrong; then we could debug and see what might be going wrong. Since you "know" the strike might be 30-120, pick a point where you know it should be ~100 and see what grdgradient says. If there is stark disagreement, use grdcut to cut out a tiny grid (say 5x5 nodes) centered on that value from your grid, rerun grdgradient on this grid to confirm there is a mismatch, and post it as a potential bug on the gmt website. > > Cheers, Paul > > On Feb 20, 2014, at 11:50 AM, Mr Abhash Kumar <[email protected]> wrote: > >> Hi, >> I used grdgradient to calculate the strike of downdip direction at every grid point of the subducting slab: >> >> grdgradient slabsurf2.grd -Dn -Sslabgradient.grd -M -V >> >> I am getting the following results: >> >> -69.9441860465 -17.0522875817 35.6361160278 >> -69.8697674419 -17.0522875817 36.5936279297 >> -69.7953488372 -17.0522875817 37.6132316589 >> -69.7209302326 -17.0522875817 38.6617622375 >> -69.6465116279 -17.0522875817 34.4591636658 >> -69.5720930233 -17.0522875817 31.943397522 >> -69.4976744186 -17.0522875817 31.6246490479 >> -69.423255814 -17.0522875817 30.8437995911 >> >> I roughly know that the strike of downdip direction should vary in the range of 30degree-120 degree in this region. Do I need to use some more functions to calculate the reasonable strike direction. I urgently need to calculate this and would be extremely grateful for any suggestions. >> >> Thanks >> Abhash kumar >> University of North Carolina at Chapel Hill >> To unsubscribe, send the message "signoff gmt-help" to [email protected] > > To unsubscribe, send the message "signoff gmt-help" to [email protected] > To unsubscribe, send the message "signoff gmt-help" to [email protected] To unsubscribe, send the message "signoff gmt-help" to [email protected]