I should have made some example code available right away. My apologies, @pwessel. Here is a bare bones version:
gmt begin deps_eddf png
gmt plot -R007:30/010:00/49:30/50:50 \
-JL008:34:13.64/50:01:59.90/49:57/50:23/15c -B \
flight.txt -i7,6 -W1p,red
gmt end show
flight.zip (3.2 KB) contains the required flight.txt
This works as expected. I get a red line on the plot.
Now for what I’m trying to achieve: Column 3 (when you start counting at 0) contains my z-values, in this case altitude information. I want to color the plotted line according to altitude with a CPT. In my understanding this can be done with -W+z -Zflight.txt -Cbuda
. But only if the supplied file has the z-values in the last column:
Alternatively, give the name of a file with one z-value (read from the last column) for each polygon in the input data.
(source)
So recycling my data file fails predictably:
gmt begin deps_eddf png
gmt plot -R007:30/010:00/49:30/50:50 \
-JL008:34:13.64/50:01:59.90/49:57/50:23/15c -B \
flight.txt -i7,6 -W+z -Zflight.txt -Cbuda
gmt end show
This code seems to wait for input which never comes and needs to be terminated.
I tried -i7,6,3
as a moonshot but got no luck:
plot [WARNING]: Number of input columns required [2] is less that implied by -i [3]
I assume this is the polygon plotting machinery complaining.
It all boils down to the question: Is there a way to get those z-values from my original data without preparing a separate file for -Z
?
I have around 4700 tracks to plot adding up to about 856 GB of ASCII-data. Or would you say it is more efficient to crunch the data into specialized files?