Re: How to plot outline of overlapping circles
Kristof Koch <[email protected]>
| Newsgroups | gmane.comp.gis.gmt.user |
|---|---|
| Message-ID | <[email protected]> |
Dear Paul, I got the grdmask route working. Thank you for your help & your suggestions. All the best, Kristof Am 11.12.2013 um 07:08 schrieb Paul Wessel <[email protected]>: > grdmath PDIST is pretty CPT intensive, but not as bad as LDIST... > You could consider doing this at -I1 and then run grdsample to resample to 0.1. The distances should change slowly enough for an interpolation. But given your different distances pr circle I would to the grdmask route instead. > > -p > > Prof. Paul Wessel, GG/SOEST/UHM > > > > > > On Dec 9, 2013, at 11:09 AM, Kristof Koch <[email protected]> wrote: > >> Paul, >> >> currently I'm toying around with your advice of using grdmath PDIST. However I need -I0.1 to get the required resolution. This is unfortunately rather CPU intensive. Reducing -Rd to the current -R is causing missing parts (circle segments) in the outline. As I'm new to grdmath I'm not sure if I'm doing something wrong there. >> >> Here is the snippet of the code I'm using: >> >> grdmath -Rd -I0.1 -fg $WORK_DIR/comfix-limit.txt PDIST = grddist.nc >> >> […] >> >> # VHF Coverage >> grdcontour \ >> grddist.nc \ >> -JL -R \ >> -A+5 \ >> -Wa1.5p,$VHF_COM_COLOR,1.5_1:0p \ >> -K -O \ >> >> $FILE >> >> Kind regards, >> Kristof >> >> >> Am 09.12.2013 um 16:27 schrieb Paul Wessel <[email protected]>: >> >>> I would compute distances from all your points on the grid using grdmath PDIST operator and then your red line is a contour in the grid, e.g., the max distance contour you choose in grdcontour. >>> >>> -p >>> >>> On Dec 9, 2013, at 3:50 AM, Kristof Koch <[email protected]> wrote: >>> >>>> Dear List, >>>> >>>> I'm plotting circles depicting the same distance around a given coordinate representing the range of a VHF transmitter. While these VHF transmitter sites are usually quite close together to get a seamless coverage, there are obviously no sites in the middle of the sea. I'm interested in the visual representation of the coverage. I'm not interested in the exact coverage of each and every single transmitter, just in the boundary where the coverage ends. >>>> >>>> Currently I'm plotting the coverage with the build in ellipse symbol (-SE) getting overlapping circles (see output.jpg; the thick white lines). I'd like to reduce the circles to the part crudely highlighted in red in desired_result.jpg representing the outer boundary of the covered area and get rid of any parts laying inside the covered area. >>>> >>>> I have currently no idea on how to achieve the desired result. Any nudge in the right direction is greatly appreciated. >>>> >>>> All the best, >>>> Kristof Koch >>>> >>>> I'm currently using >>>> >>>> gmt - Version 5.1.0 (r12452) [64-bit] on >>>> Ubuntu 12.04.3 LTS (GNU/Linux 2.6.32-042stab081.5 x86_64) >>>> >>>> The part of the script generating the white circles in the attached images: >>>> >>>> cat > $WORK_DIR/com_site.txt << END >>>> -22.606 63.985 0 1111.2 1111.2 >>>> -19 63.4 0 1111.2 1111.2 >>>> -7.588 62.107 0 1111.2 1111.2 >>>> END >>>> >>>> psxy \ >>>> $WORK_DIR/com_site.txt \ >>>> -J -R \ >>>> -SE -Wfat,white \ >>>> -K -O \ >>>> >> $FILE >>>> >>>> <output.jpg> >>>> >>>> <desired_result.jpg> >>>> To unsubscribe, send the message "signoff gmt-help" to [email protected] >>> >>> To unsubscribe, send the message "signoff gmt-help" to [email protected] >> >> To unsubscribe, send the message "signoff gmt-help" to [email protected] > > To unsubscribe, send the message "signoff gmt-help" to [email protected] To unsubscribe, send the message "signoff gmt-help" to [email protected]