grdcontour - issue warning if no contours are drawn and finalize plot and some other minor issues #597
Description
- Giving a
grdcontour [..] -L<low/high>which yields no contours should issue a warning as well as finalizing the plot (even if no contours were drawn).
~/temp 08:46:34 $ grdimage -JS0/90/10c -RNO @earth_relief_30m.grd -P -K > plot.ps
~/temp 08:46:45 $ grdcontour -J -R @earth_relief_30m.grd -O -C1000 -Bafg -L10000/100000 >> plot.ps
~/temp 08:46:48 $ psconvert -Tf -A plot.ps
psconvert [ERROR]: plot.ps: GMT PS format detected but file is not finalized. Maybe a -K in excess? plot.pdf could be messed up.
- Also, giving
-C0(zero contour interval) does not really makes sense, right? E.g.
$ grdcontour -JS0/90/10c -RNO @earth_relief_30m.grd -C0 -Bafg > 0_cont_int.ps
But it will plot the same as giving -C+0
$ grdcontour -JS0/90/10c -RNO @earth_relief_30m.grd -C+0 -Wthick,red -Bafg > plot_0_cont_only.ps
Maybe this is wanted, but an alternative would be to issue warning/information.
- Giving this command gives strange output, but seems to work fine.
$ grdcontour -JS0/90/10c -RNO @earth_relief_30m.grd -C1 -Bafg > plot.ps
grdcontour [ERROR]: Error in map_wesn_clip: odd number of crossings?grdcontour [ERROR]: Error in map_wesn_clip: odd number of crossings?grdcontour [ERROR]: Error in map_wesn_clip: odd number of crossings?grdcontour [ERROR]: Error in map_wesn_clip: odd number of crossings?
The error disappears if the contour interval (-C) is > 12.