Need help on grdcut and grdtrack

[Santosh Panda-2]

Hi Everyone,

I have a raster image in Geosoft .GRD format, I want to cut a subset from
this image using grdcut command and sample it using a sequence of XY point
using grdtrack command. As GMT doesn't read Geosoft .GRD format, I exported
this raster image into Surfer V6(.GRD) format and GMT reads this format.

santosh@santosh-laptop:~/Documents/DATA/GEOPHYSICS$ grdinfo RES140K_Surfer6.GRD
RES140K_Surfer6.GRD: Title: Grid originally in Surfer 6 format
RES140K_Surfer6.GRD: Command:
RES140K_Surfer6.GRD: Remark:
RES140K_Surfer6.GRD: Gridline node registration used
RES140K_Surfer6.GRD: Grid file format: sf (# 6)
RES140K_Surfer6.GRD: x_min: 262640 x_max: 507415 x_inc: 25 name: x nx: 9792
RES140K_Surfer6.GRD: y_min: 6.92688e+06 y_max: 7.12278e+06 y_inc: 25 name: y
ny: 7837
RES140K_Surfer6.GRD: z_min: 0.001 z_max: 60000 name: z
RES140K_Surfer6.GRD: scale_factor: 1 add_offset: 0

It is in UTM_NAD_1927_Z7 projection.
I used following commands to cut a subset, but got error message

santosh@santosh-laptop:~/Documents/DATA/GEOPHYSICS$ grdcut
RES140K_Surfer6.GRD -Gtgrid.grd -R348518/385785/7021212/7061749 -V
grdcut: GMT ERROR: (x_max-x_min) must equal (NX + eps) * x_inc), where NX is
an integer and |eps| <= 0.0001.
grdcut: GMT ERROR: (y_max-y_min) must equal (NY + eps) * y_inc), where NY is
an integer and |eps| <= 0.0001.
grdcut: Please select compatible -R and -I values [tgrid.grd]

Then, I changed -R parameters to lat long and tried, but got following error
message. I am sure that the subset I am using is well within the raster data

santosh@santosh-laptop:~/Documents/DATA/GEOPHYSICS$ grdcut
RES140K_Surfer6.GRD -Gtgrid.grd -R-144.059/-143.732/63.585/63.653 -V
grdcut: Subset exceeds data domain!

I also tried to sample this raster image using the following command, but...

santosh@santosh-laptop:~/Documents/DATA/GEOPHYSICS$ grdtrack testsampleXY
-GRES140K_Surfer6.GRD -Qn -H -V > tsampled
GMT_grd_is_global: no!
GMT_grd_is_global: no!
GMT_boundcond_param_prep determined edgeinfo: gn = 0, gs = 0, nxp = 0, nyp = 0
grdtrack: Sampled 0 points from grid RES140K_Surfer6.GRD (9792 x 7837)

I think, here I am lacking the basic understanding on how GMT work? totally
CONFUSED???
I would highly appreciate any suggestion or help on this problem...

Thanks,
Santosh

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