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GMT Delauny triangulate

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	GMT Delauny triangulate by Genru Xiao :: Rate this Message: Reply to Author \| View Threaded \| Show Only this Message Dear Admin I use triangulate under GMT 4.0 to form a triangulation with command line: triangulate data.txt -M -R96/112/40/54 -Jm0.5 \|psxy -M -R96/112/40/54 -Jm0.5 -W20/20/250 > tri.ps while under MATLAB 7(R14),I also get a triangulation with command line tri = delaunay(L,B) triplot(tri,L,B, 'red') and I am confused while there exist some difference between the outputs. Can you tell me how to use the parameters to get the same output? Thanks attached file is the data.txt and the output pictures I clip . Best regards Xiao Genru -- <><><><><><><><><><><><><><><><><><><><><><><><><><><> Dr. Genru Xiao GPS Center of Institute of Geology,China Earthquake Administration Beijing 100029, China Tel. 86-10-62009178 xiaogenru@... xgr541@... <><><><><><><><><><><><><><><><><><><><><><><><><><><> To unsubscribe, send the message "signoff gmt-help" to listserv@... 96.25 46.55 96.78 47.61 97.05 41.85 97.98 49.08 98.10 44.20 98.50 47.20 98.80 48.71 98.98 50.18 100.09 49.66 100.20 40.98 100.79 44.47 101.31 43.09 101.44 45.67 101.61 50.10 101.80 47.52 102.21 51.76 102.81 49.45 103.02 46.12 103.22 52.26 103.52 48.80 103.64 51.68 104.32 52.22 104.43 43.59 104.51 40.74 104.89 51.85 105.50 53.06 106.02 51.17 106.22 45.80 106.25 50.23 106.58 52.79 106.98 41.43 107.05 47.87 107.62 51.81 107.74 53.33 108.24 52.97 109.15 52.12 110.59 47.26 110.85 48.52 109.10 43.80 gmt.jpg (215K) Download Attachment matlab.jpg (583K) Download Attachment
	Re: GMT Delauny triangulate by Peter Schmidt-3 :: Rate this Message: Reply to Author \| View Threaded \| Show Only this Message Hi trying to reproduce Xiao's problems using his attached data file and specified command I get the error message: me:~> triangulate: GMT SYNTAX ERROR. Must specify -R, -I, -G for gridding which I do not really understand based on the information on the man page. I'm running GMT 4.4.0, should I upgrade (i.e. is this a bug and has it been taken care, or am I just missing something)? BTW. In the last example of the man page I assume that: "triangulate samples.xyz -M -R-100/-90/30/34 -JM15c \| psxy -M OPR(R)-100/-90/30/34 -JM15c -W0.5p -B1 > network.ps" should read: "triangulate samples.xyz -M -R-100/-90/30/34 -JM15c \| psxy -M -R-100/-90/30/34 -JM15c -W0.5p -B1 > network.ps" A suggestion/hint for Xiao: You might want to make sure that the projection is the same when using matlab and gmt to do delaunay trinagulation (matlabs equivalent would be -Jx in gmt i guess). For one thing its hard to see the differences between your figures from a visual inspection if the projections differ. My money is also on that the difference in projection is part of the difference in produced triangulation, to cite the man page "If a map projection (give -R and -J) is chosen then it is applied before the triangulation is calculated." which I would interpret as change projection = change resulting triangulation regP Genru Xiao wrote: > Dear Admin > > I use triangulate under GMT 4.0 to form a triangulation with > command line: > > triangulate data.txt -M -R96/112/40/54 -Jm0.5 \|psxy > -M -R96/112/40/54 -Jm0.5 -W20/20/250 > tri.ps <http://tri.ps/> > ** > while under MATLAB 7(R14),I also get a triangulation with > command line > > tri = delaunay(L,B) > triplot(tri,L,B, 'red') > ** > and I am confused while there exist some difference between the > outputs. > Can you tell me how to use the parameters to get the same output? > Thanks > > attached file is the data.txt and the output pictures I clip . > > > Best regards > > Xiao Genru > * > * > > -- > <><><><><><><><><><><><><><><><><><><><><><><><><><><> > Dr. Genru Xiao > GPS Center of Institute of Geology,China Earthquake Administration > Beijing 100029, China > Tel. 86-10-62009178 > xiaogenru@... <mailto:xiaogenru@...> xgr541@... > <mailto:xgr541@...> > <><><><><><><><><><><><><><><><><><><><><><><><><><><> > To unsubscribe, send the message "signoff gmt-help" to > listserv@... > ------------------------------------------------------------------------ > > ------------------------------------------------------------------------ > -- ****************************************************************************** Peter Schmidt Tel: +46-18-4717104 PhD Student Mobile: +46-73-3190975 Dept. of Earth Sciences e-mail: peter.schmidt@... Geophysics http://www.geofys.uu.se/?q=view/home/75 Uppsala University Villavagen 16 SE-75236 Uppsala ****************************************************************************** To unsubscribe, send the message "signoff gmt-help" to listserv@...
	Re: GMT Delauny triangulate by Milton P. Plasencia Linares :: Rate this Message: Reply to Author \| View Threaded \| Show Only this Message Hi Xiao, Using your data and script I obtain the attached figure, I use GMT4.5.1 last version on fedora 11. Cheers ******************************** Milton P. PLASENCIA LINARES Dipartimento Centro di Ricerche Sismologiche Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS Borgo Grotta Gigante 42/C (34010) Sgonico - TRIESTE - ITALIA Tel: +39-040-2140305 Fax: +39-040-327307 E-mail: mplasencia@... ASAIN (Antarctic Seismographic Argentinean Italian Network) ******************************* Quoting "Genru Xiao" <xiaogenru@...>: > Dear Admin > > I use triangulate under GMT 4.0 to form a triangulation with command > line: > > triangulate data.txt -M -R96/112/40/54 -Jm0.5 \|psxy -M > -R96/112/40/54 -Jm0.5 -W20/20/250 > tri.ps > ** > while under MATLAB 7(R14),I also get a triangulation with command line > > tri = delaunay(L,B) > triplot(tri,L,B, 'red') > ** > and I am confused while there exist some difference between the > outputs. > Can you tell me how to use the parameters to get the same output? > Thanks > > attached file is the data.txt and the output pictures I clip . > > Best regards > > Xiao Genru > * > * > > -- > <><><><><><><><><><><><><><><><><><><><><><><><><><><> > Dr. Genru Xiao > GPS Center of Institute of Geology,China Earthquake Administration > Beijing 100029, China > Tel. 86-10-62009178 > xiaogenru@... xgr541@... > <><><><><><><><><><><><><><><><><><><><><><><><><><><> > > To unsubscribe, send the message "signoff gmt-help" to listserv@... > ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program. To unsubscribe, send the message "signoff gmt-help" to listserv@... tri.png (18K) Download Attachment
	Re: GMT Delauny triangulate by Genru Xiao :: Rate this Message: Reply to Author \| View Threaded \| Show Only this Message hi thanks you, the figure is same ,should I update my GMT to 4.5.1 , is it the algorithm of GMT 4.1 and 4.5 adopted different , does there have detail documents? 2009/10/22 Milton P. Plasencia Linares <mplasencia@...> Hi Xiao, Using your data and script I obtain the attached figure, I use GMT4.5.1 last version on fedora 11. Cheers ******************************** Milton P. PLASENCIA LINARES Dipartimento Centro di Ricerche Sismologiche Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS Borgo Grotta Gigante 42/C (34010) Sgonico - TRIESTE - ITALIA Tel: +39-040-2140305 Fax: +39-040-327307 E-mail: mplasencia@... ASAIN (Antarctic Seismographic Argentinean Italian Network) ******************************* Quoting "Genru Xiao" <xiaogenru@...>: Dear Admin I use triangulate under GMT 4.0 to form a triangulation with command line: triangulate data.txt -M -R96/112/40/54 -Jm0.5 \|psxy -M -R96/112/40/54 -Jm0.5 -W20/20/250 > tri.ps ** while under MATLAB 7(R14),I also get a triangulation with command line tri = delaunay(L,B) triplot(tri,L,B, 'red') ** and I am confused while there exist some difference between the outputs. Can you tell me how to use the parameters to get the same output? Thanks attached file is the data.txt and the output pictures I clip . Best regards Xiao Genru * * -- <><><><><><><><><><><><><><><><><><><><><><><><><><><> Dr. Genru Xiao GPS Center of Institute of Geology,China Earthquake Administration Beijing 100029, China Tel. 86-10-62009178 xiaogenru@... xgr541@... <><><><><><><><><><><><><><><><><><><><><><><><><><><> To unsubscribe, send the message "signoff gmt-help" to listserv@... ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program. To unsubscribe, send the message "signoff gmt-help" to listserv@... -- <><><><><><><><><><><><><><><><><><><><><><><><><><><> Dr. Genru Xiao GPS Center of Institute of Geology,China Earthquake Administration Beijing 100029, China Tel. 86-10-62009178 xiaogenru@... xgr541@... <><><><><><><><><><><><><><><><><><><><><><><><><><><> To unsubscribe, send the message "signoff gmt-help" to listserv@...
	Re: GMT Delauny triangulate by Milton P. Plasencia Linares :: Rate this Message: Reply to Author \| View Threaded \| Show Only this Message Hi, Ok, update your GMT version, i not have detail, but you can see man or web page or the source code, from 4.1 to 4.5.1 GMT has had significant changes, here the gurus can help you. Cheers ******************************** Milton P. PLASENCIA LINARES Dipartimento Centro di Ricerche Sismologiche Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS Borgo Grotta Gigante 42/C (34010) Sgonico - TRIESTE - ITALIA Tel: +39-040-2140305 Fax: +39-040-327307 E-mail: mplasencia@... ASAIN (Antarctic Seismographic Argentinean Italian Network) ***************************** Quoting "Genru Xiao" <xiaogenru@...>: > hi > thanks you, the figure is same ,should I update my GMT to 4.5.1 , is it > the algorithm of GMT 4.1 and 4.5 adopted different , does there have detail > documents? > > 2009/10/22 Milton P. Plasencia Linares <mplasencia@...> > >> >> Hi Xiao, >> Using your data and script I obtain the attached figure, >> I use GMT4.5.1 last version on fedora 11. >> >> Cheers >> >> >> ****************************** >> Milton P. PLASENCIA LINARES >> >> Dipartimento Centro di Ricerche Sismologiche >> Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS >> >> Borgo Grotta Gigante 42/C >> (34010) Sgonico - TRIESTE - ITALIA >> Tel: +39-040-2140305 >> Fax: +39-040-327307 >> >> E-mail: mplasencia@... >> >> ASAIN (Antarctic Seismographic Argentinean Italian Network) >> ******************************* >> >> >> >> Quoting "Genru Xiao" <xiaogenru@...>: >> >> Dear Admin >>> >>> I use triangulate under GMT 4.0 to form a triangulation with command >>> line: >>> >>> triangulate data.txt -M -R96/112/40/54 -Jm0.5 \|psxy -M >>> -R96/112/40/54 -Jm0.5 -W20/20/250 > tri.ps >>> ** >>> while under MATLAB 7(R14),I also get a triangulation with command >>> line >>> >>> tri = delaunay(L,B) >>> triplot(tri,L,B, 'red') >>> ** >>> and I am confused while there exist some difference between the >>> outputs. >>> Can you tell me how to use the parameters to get the same output? >>> Thanks >>> >>> attached file is the data.txt and the output pictures I clip . >>> >>> Best regards >>> >>> Xiao Genru >>> * >>> * >>> >>> -- >>> <><><><><><><><><><><><><><><><><><><><><><><><><><><> >>> Dr. Genru Xiao >>> GPS Center of Institute of Geology,China Earthquake Administration >>> Beijing 100029, China >>> Tel. 86-10-62009178 >>> xiaogenru@... xgr541@... >>> <><><><><><><><><><><><><><><><><><><><><><><><><><><> >>> >>> To unsubscribe, send the message "signoff gmt-help" to >>> listserv@... >>> >>> >> >> >> ---------------------------------------------------------------- >> This message was sent using IMP, the Internet Messaging Program. >> >> >> To unsubscribe, send the message "signoff gmt-help" to listserv@... >> > > > > -- > <><><><><><><><><><><><><><><><><><><><><><><><><><><> > Dr. Genru Xiao > GPS Center of Institute of Geology,China Earthquake Administration > Beijing 100029, China > Tel. 86-10-62009178 > xiaogenru@... xgr541@... > <><><><><><><><><><><><><><><><><><><><><><><><><><><> > > To unsubscribe, send the message "signoff gmt-help" to listserv@... > > > Email secured by CeSIT Check Point gateway > ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program. To unsubscribe, send the message "signoff gmt-help" to listserv@...
	Re: GMT Delauny triangulate by Joaquim Luis-2 :: Rate this Message: Reply to Author \| View Threaded \| Show Only this Message GMT has two different algorithms, Watson & Shewchuk. Which one is used is decided at compile time. Since you are using the Win version I'm nearly sure that 4.0 was compiled with Watson's while 4.5.1 is compiled with Shewchuk. Matlab doesn't use any of those. It uses qhull. If the result is different I'm afraid there is nothing you can do to change it. Notice that you could also ask to Matworks (Matlab) why it doesn't give the same result as GMT. Joaquim Luis On Thu, Oct 22, 2009 at 11:53 AM, Genru Xiao <xiaogenru@...> wrote: hi thanks you, the figure is same ,should I update my GMT to 4.5.1 , is it the algorithm of GMT 4.1 and 4.5 adopted different , does there have detail documents? 2009/10/22 Milton P. Plasencia Linares <mplasencia@...> Hi Xiao, Using your data and script I obtain the attached figure, I use GMT4.5.1 last version on fedora 11. Cheers ******************************** Milton P. PLASENCIA LINARES Dipartimento Centro di Ricerche Sismologiche Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS Borgo Grotta Gigante 42/C (34010) Sgonico - TRIESTE - ITALIA Tel: +39-040-2140305 Fax: +39-040-327307 E-mail: mplasencia@... ASAIN (Antarctic Seismographic Argentinean Italian Network) ******************************* Quoting "Genru Xiao" <xiaogenru@...>: Dear Admin I use triangulate under GMT 4.0 to form a triangulation with command line: triangulate data.txt -M -R96/112/40/54 -Jm0.5 \|psxy -M -R96/112/40/54 -Jm0.5 -W20/20/250 > tri.ps ** while under MATLAB 7(R14),I also get a triangulation with command line tri = delaunay(L,B) triplot(tri,L,B, 'red') ** and I am confused while there exist some difference between the outputs. Can you tell me how to use the parameters to get the same output? Thanks attached file is the data.txt and the output pictures I clip . Best regards Xiao Genru * * -- <><><><><><><><><><><><><><><><><><><><><><><><><><><> Dr. Genru Xiao GPS Center of Institute of Geology,China Earthquake Administration Beijing 100029, China Tel. 86-10-62009178 xiaogenru@... xgr541@... <><><><><><><><><><><><><><><><><><><><><><><><><><><> To unsubscribe, send the message "signoff gmt-help" to listserv@... ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program. To unsubscribe, send the message "signoff gmt-help" to listserv@... -- <><><><><><><><><><><><><><><><><><><><><><><><><><><> Dr. Genru Xiao GPS Center of Institute of Geology,China Earthquake Administration Beijing 100029, China Tel. 86-10-62009178 xiaogenru@... xgr541@... <><><><><><><><><><><><><><><><><><><><><><><><><><><> To unsubscribe, send the message "signoff gmt-help" to listserv@... To unsubscribe, send the message "signoff gmt-help" to listserv@...
	Re: GMT Delauny triangulate by Genru Xiao :: Rate this Message: Reply to Author \| View Threaded \| Show Only this Message OK，I will try and if possible I will post the results . thanks 2009/10/22 J Luis <jmfluis@...> GMT has two different algorithms, Watson & Shewchuk. Which one is used is decided at compile time. Since you are using the Win version I'm nearly sure that 4.0 was compiled with Watson's while 4.5.1 is compiled with Shewchuk. Matlab doesn't use any of those. It uses qhull. If the result is different I'm afraid there is nothing you can do to change it. Notice that you could also ask to Matworks (Matlab) why it doesn't give the same result as GMT. Joaquim Luis On Thu, Oct 22, 2009 at 11:53 AM, Genru Xiao <xiaogenru@...> wrote: hi thanks you, the figure is same ,should I update my GMT to 4.5.1 , is it the algorithm of GMT 4.1 and 4.5 adopted different , does there have detail documents? 2009/10/22 Milton P. Plasencia Linares <mplasencia@...> Hi Xiao, Using your data and script I obtain the attached figure, I use GMT4.5.1 last version on fedora 11. Cheers ******************************** Milton P. PLASENCIA LINARES Dipartimento Centro di Ricerche Sismologiche Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS Borgo Grotta Gigante 42/C (34010) Sgonico - TRIESTE - ITALIA Tel: +39-040-2140305 Fax: +39-040-327307 E-mail: mplasencia@... ASAIN (Antarctic Seismographic Argentinean Italian Network) ******************************* Quoting "Genru Xiao" <xiaogenru@...>: Dear Admin I use triangulate under GMT 4.0 to form a triangulation with command line: triangulate data.txt -M -R96/112/40/54 -Jm0.5 \|psxy -M -R96/112/40/54 -Jm0.5 -W20/20/250 > tri.ps ** while under MATLAB 7(R14),I also get a triangulation with command line tri = delaunay(L,B) triplot(tri,L,B, 'red') ** and I am confused while there exist some difference between the outputs. Can you tell me how to use the parameters to get the same output? Thanks attached file is the data.txt and the output pictures I clip . Best regards Xiao Genru * * -- <><><><><><><><><><><><><><><><><><><><><><><><><><><> Dr. Genru Xiao GPS Center of Institute of Geology,China Earthquake Administration Beijing 100029, China Tel. 86-10-62009178 xiaogenru@... xgr541@... <><><><><><><><><><><><><><><><><><><><><><><><><><><> To unsubscribe, send the message "signoff gmt-help" to listserv@... ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program. To unsubscribe, send the message "signoff gmt-help" to listserv@... -- <><><><><><><><><><><><><><><><><><><><><><><><><><><> Dr. Genru Xiao GPS Center of Institute of Geology,China Earthquake Administration Beijing 100029, China Tel. 86-10-62009178 xiaogenru@... xgr541@... <><><><><><><><><><><><><><><><><><><><><><><><><><><> To unsubscribe, send the message "signoff gmt-help" to listserv@... To unsubscribe, send the message "signoff gmt-help" to listserv@... -- <><><><><><><><><><><><><><><><><><><><><><><><><><><> Dr. Genru Xiao GPS Center of Institute of Geology,China Earthquake Administration Beijing 100029, China Tel. 86-10-62009178 xiaogenru@... xgr541@... <><><><><><><><><><><><><><><><><><><><><><><><><><><> To unsubscribe, send the message "signoff gmt-help" to listserv@...
	Re: GMT Delauny triangulate by Genru Xiao :: Rate this Message: Reply to Author \| View Threaded \| Show Only this Message the following is the replied from Mathworks user group "Damian Sheehy" <Damian.Sheehy@...> wrote in message <hbpq2g$d3u$1@...>... > Xiao, > > If the topology of the triangulation you are plotting is different, then it > is probably due to degeneracy. > Delaunay triangulations are not unique in the presence of degeneracies. > > With respect to 2D triangulations, it means that if you have 4 cocircular > points in the triangulation > > the topology can either be like this ; > > > > +-----+ > > \| \ \| > > \| \ \| > \| \ \| > \| \ \| > +-----+ > > Or like this; > > +-----+ > > \| / \| > > \| / \| > \| / \| > \| / \| > +-----+ > > Both are valid Delaunay triangulations. > > You can spot these degeneracies as follows; > tri = delaunay(L,B) > triplot(tri,L,B) % Blue > hold on > voronoi(L,B,tri, 'r') > hold off > > > In the figure look for vertices in the (red) Voronoi diagram that have 4 or > more edges emanating from the vertex. > This may be a degenerate vertex and the corresponding triangles are likely > to have different topology. > > If this does not explain the differences you are seeing let me know. > > > Damian > 2009/10/22 Genru Xiao <xiaogenru@...> OK，I will try and if possible I will post the results . thanks 2009/10/22 J Luis <jmfluis@...> GMT has two different algorithms, Watson & Shewchuk. Which one is used is decided at compile time. Since you are using the Win version I'm nearly sure that 4.0 was compiled with Watson's while 4.5.1 is compiled with Shewchuk. Matlab doesn't use any of those. It uses qhull. If the result is different I'm afraid there is nothing you can do to change it. Notice that you could also ask to Matworks (Matlab) why it doesn't give the same result as GMT. Joaquim Luis On Thu, Oct 22, 2009 at 11:53 AM, Genru Xiao <xiaogenru@...> wrote: hi thanks you, the figure is same ,should I update my GMT to 4.5.1 , is it the algorithm of GMT 4.1 and 4.5 adopted different , does there have detail documents? 2009/10/22 Milton P. Plasencia Linares <mplasencia@...> Hi Xiao, Using your data and script I obtain the attached figure, I use GMT4.5.1 last version on fedora 11. Cheers ******************************** Milton P. PLASENCIA LINARES Dipartimento Centro di Ricerche Sismologiche Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS Borgo Grotta Gigante 42/C (34010) Sgonico - TRIESTE - ITALIA Tel: +39-040-2140305 Fax: +39-040-327307 E-mail: mplasencia@... ASAIN (Antarctic Seismographic Argentinean Italian Network) ******************************* Quoting "Genru Xiao" <xiaogenru@...>: Dear Admin I use triangulate under GMT 4.0 to form a triangulation with command line: triangulate data.txt -M -R96/112/40/54 -Jm0.5 \|psxy -M -R96/112/40/54 -Jm0.5 -W20/20/250 > tri.ps ** while under MATLAB 7(R14),I also get a triangulation with command line tri = delaunay(L,B) triplot(tri,L,B, 'red') ** and I am confused while there exist some difference between the outputs. Can you tell me how to use the parameters to get the same output? Thanks attached file is the data.txt and the output pictures I clip . Best regards Xiao Genru * * -- <><><><><><><><><><><><><><><><><><><><><><><><><><><> Dr. Genru Xiao GPS Center of Institute of Geology,China Earthquake Administration Beijing 100029, China Tel. 86-10-62009178 xiaogenru@... xgr541@... <><><><><><><><><><><><><><><><><><><><><><><><><><><> To unsubscribe, send the message "signoff gmt-help" to listserv@... ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program. To unsubscribe, send the message "signoff gmt-help" to listserv@... -- <><><><><><><><><><><><><><><><><><><><><><><><><><><> Dr. Genru Xiao GPS Center of Institute of Geology,China Earthquake Administration Beijing 100029, China Tel. 86-10-62009178 xiaogenru@... xgr541@... <><><><><><><><><><><><><><><><><><><><><><><><><><><> To unsubscribe, send the message "signoff gmt-help" to listserv@... To unsubscribe, send the message "signoff gmt-help" to listserv@... -- <><><><><><><><><><><><><><><><><><><><><><><><><><><> Dr. Genru Xiao GPS Center of Institute of Geology,China Earthquake Administration Beijing 100029, China Tel. 86-10-62009178 xiaogenru@... xgr541@... <><><><><><><><><><><><><><><><><><><><><><><><><><><> -- <><><><><><><><><><><><><><><><><><><><><><><><><><><> Dr. Genru Xiao GPS Center of Institute of Geology,China Earthquake Administration Beijing 100029, China Tel. 86-10-62009178 xiaogenru@... xgr541@... <><><><><><><><><><><><><><><><><><><><><><><><><><><> To unsubscribe, send the message "signoff gmt-help" to listserv@...