In respect to Sphdistance

Q&A
1

Good afternoon all,
Please in respect to my previous post about plotting of Sphdistance
Below is the correct data, the code and the plot that I got. please, I need some to help me out

##long. lat. Up
20.8109 -32.3814 0.105569
23.9926 -30.6652 0.163773
27.7072 -25.887 0.52145
19.2231 -34.4246 -0.521479
27.687 -25.8901 0.446383
25.54 -25.805 -0.131858
28.224 -25.7463 -0.111896
28.224 -25.7463 -1.05978
32.0784 -28.7955 -0.213953
17.8792 -29.6693 0.356411
20.8105 -32.3802 -1.46546
30.384 -23.0799 -0.194708
31.4209 -28.2931 1.67982
28.6725 -31.5488 0.692075
37.861 -46.876 0.689517
28.224 -25.7465 -0.585269
28.224 -25.7465 6.71353
26.716 -30.6798 -0.0581042
26.2978 -29.1037 0.494585
27.4291 -32.8637 0.971616
27.7766 -25.6358 -0.250168
28.7327 -25.8033 -0.286305
18.4897 -34.3533 -0.195013
26.5072 -33.3201 0.261246
24.5345 -32.248 -0.718806
28.3729 -26.5085 1.24404
27.686 -25.8903 1.18585
30.0688 -30.1461 0.347937
24.8065 -28.743 4.06764
23.4325 -27.4608 1.1718
29.4221 -30.5645 1.04107
27.7663 -26.0829 -2.85082
27.2401 -27.6636 -1.17704
18.7308 -33.4638 0.288675
29.4542 -25.7738 1.0483
29.9874 -29.2089 0.246554

gmt begin map pdf
gmt set MAP_FRAME_TYPE plain
gmt set FONT_LABEL 16p
gmt makecpt -Cjet -T-15/30/2
gmt pscoast -R16/33/-35/-22 -JM20c -BWSne -Baf -I1/1p,0/200/251 -W1,black -Gwhite -Di -N2/0.25p,black -Na/0.5,black -Swhite > SA.ps
gmt sphtriangulate SA.dat -Qv -D > t.txt
gmt sphdistance -R16/33/-35/-22 -I1 -Q -Gsphdistance.nc -Lk
gmt grdcontour sphdistance.nc -JM20c -C200 -A1000 -Bafg
gmt end show

image
image808×688 55.3 KB

2

When we open a new Topic, we have to select from

image
image992×751 50.6 KB

Why do you select to post under GMT.jl category if your post has nothing to do with the GMT Julia wrapper?

3

Maybe the same reason the posted script has an obvious error that yield clear error messages and has features (coloured symbols) not produced by the script?

Your sphdistance -Q option is not given the argument: the file produced by sphtriangulate

4

Regarding your duplicates, I am sure you looked at the documentation for sphtriangulate and found

Notes

The STRIPACK algorithm and implementation expect that there are no duplicate points in the input. It is best that the user ensures that this is the case. GMT has tools, such as blockmean and others, to combine close points into single entries. Also, sphtriangulate has a -D option to determine and exclude duplicates, but it is a very brute-force yet exact comparison that is very slow for large data sets. Detection of duplicates in the STRIPACK library will exit the module.

5

okay then let me reduce the data to see if nit will work.
Thanks so much
best regards