Psxy/plot -Sq option +t/T modifiers

In the process of trying to calculate coordinates for equally spaced points along a line/track (every 25 km in the sample below), I noticed that the psxy / plot -Sq...:+t option isn’t producing the output that I expected (the angle is included, not just the cumulative distance) and the +T modifier results in a psxy error Option -S: Parsing failure.

  1. Is the +t modifier supposed to output the distance along the line/track and the annotation angle?
  2. Am I doing something wrong to get the parsing error with the +T modifier?
cat << EOL > tmp.txt
0.1 0.1
0.1 0.9
EOL
# with "+t" -> lon, lat, angle, distance
gmt psxy tmp.txt -R0/1/0/1 -JM6c -N -SqD25k:+LD+ttmp1.pts > /dev/null
# with "+T" -> parsing error
gmt psxy tmp.txt -R0/1/0/1 -JM6c -N -SqD25k:+LD+Ttmp2.pts > /dev/null

I’m using GMT 6.1.1 installed with homebrew on macOS 10.14

Thank you,
Jason

  1. Yes, it should output distance. The output is lon, lat, angle, distance for the development version. I will check whether this changed since 6.1.1. Edit: I am unable to reproduce the problem and get x,y, angle, label (distance) using both dev and 6.1.1.

  2. No, you’re not doing anything wrong. The +T option is defunct. The documentation was fixed in a recent issue, see https://github.com/GenericMappingTools/gmt/issues/4218 for the discussion.

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I have fixed the problem that it resulted in an error. While +T is deprecated, it should at least default to +t behavior, which it now will do once my PR is merged.

Now merged into master. Thanks for the report.

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