Re: [GRASS-user] Calculating Length Between Points On Stream Network
Rich Shepard pisze: I have a vector map of a stream network and want to find the distance between two points on the main stem. I have the geographic coordinates of each point on the line representing the stream. I tried v.what but I'm not comfortable that gave me the correct answer. The line between the two points is multiple segments where there are confluences with feeder streams. What module, used with the GUI or on the command line, will allow me to calculate the distance along the stream between two identified points? Rich ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user try to use r.stream.pos but it work only with raster map J. ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] Is there a "grassflyer.lyx" file available?
Is there anybody using LyX who already has a "grassflyer.lyx" or similar? LyX (1.6.5) won't import out of the box the ".tex" file. Thanks, Nikos ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] High resolution dem
[long, but hopefully interesting & check out the link to the new surface trials wiki page in the middle] Frank Broniewski wrote: > I am trying to create a high resolution dem from contour lines Until > now all my tries where not successful. At first I tried r.surf.contour, > but since my interpolation region is not rectangular and the contours > are not evenly distributed (rough terrain), the result was > unfortunately not usable really? how did it go wrong? For me it has always worked beautifully, and I'm working in mountains where the terrain is about as rough as you can get. approx 16000x16000 cell region size without problems. > ( but it took around 7 days to compute, that > alone was already impressive ;) ) yes, the search algorithm is very inefficient for areas with a lot of flat lands where it has to search for a long time to find the nearest contour line. (so in that way it actually likes rough terrain) > My contour map is a combinatin of a national contour line map (5m vert. > resolution) and contours from SRTM with 20m vert. resolution. are you sure that the two are in agreement? do the contour lines cross or does the hole in the srtm avoid that? > I created a "hole" in the srtm contours for the national contour map > and patched both together to avoid large gaps with no height values > (mostly for r.surf.contour) um, why not use srtm directly instead of doing srtm -> contours -> dem? srtm's native form is raster, not contour lines. ... and then patch in the hi-res r.surf.* result in the middle. > My region is 17.000 x 13.000 cells wide (5m horiz. resolution). So my that is getting big, but shouldn't be too bad. except perhaps for v.surf.rst (and r.fillnulls which uses it). hmmm... I wonder if it would speed up r.fillnulls & save lots of memory if we added the no-table and no-topology -b and -z flags to the r.to.vect step in it? > current approach is to use small regions (2000 x 2000) to calculate > small subsets of the dem. Because of the algo used by v.surf.rst to > create the dem the neighboring tiles do have different height values > calculated at the borders. So it was not possible to just create the > tiles and patch them together. I suspect this is making it more complicated than it has to be. Perhaps try running v.generalize before v.surf.rst? > My next approach used an overlapping of 20 cells for each tile and a > moving window average to calculate the mean of the overlapping tiles. > The result was quite good, but the moving window approach resulted in > null values where one tile ended and the other started .. > (similar to the slope and aspect maps, where there is a 1 cell null > border around the map in comparison to the input dem). these are caused because it takes into account all the cells around it, and at the edges some of those are unknown (out of region is equivalent to NULL). > Unfortunately I was not able to remove the null values satisfactorily. > r.fillnulls fails because of the large region, and r.resamp.rst does > the job not very well. The stripes are still visible, though filled > with values. the usual way would be to use one of the r.surf.* or r.resamp* modules, then use r.patch with the old map in the foreground and the interpolated map in the background filling in any gaps. > When calculating a derivate from the dem, like aspect, the errors from > filling null values are quite obvious. I take it the vertical jumps between tile edges are rather large? > So to make my long text short: Is there a technique to combine two or > more raster dem with (or without overlapping) with good > transition/intersection (don't know the correct word) between two > tiles? usually it would be a matter of making the overlaps big enough, and then using r.series or something to patch them together taking the average. I guess it would be better bias away from map edges somehow? Not sure how to do that beyond cropping a set number of cells with an inverse r.grow. but again 13k * 17k cells is not that huge so you shouldn't need to tile. (except for r.fillnulls/v.surf.rst). maybe r.surf.idw(2) or r.surf.nnbathy from wiki addons helps here? > If necessary I can illustrate my efforts by creating a web page or > similar ... I am curious to know what the problem with r.surf.contour was. Usually it does a great job as long as you take a moment to work around the integer and NULL/0 issues. I decided to do some tests using different methods on the 1m contour lines from the NC sample dataset. Results are here: http://grass.osgeo.org/wiki/Contour_lines_to_DEM John Tate wrote: > and then patched (r.patch) them all together. The patching should > average out any differences. r.patch doesn't average, it uses the cell from the first-listed raster map which contains a non-NULL cell. Later-listed rasters fill in the gaps until there are no more gaps or no more maps. r.series will merge overlapping maps using an average though. > I then cropped out each 1km tile (1000x
Re: [GRASS-user] Calculating Length Between Points On Stream Network
On Sat, 27 Feb 2010, Rich Shepard wrote: 242856.60 431305.07 242551.88 432149.70 Oops! I forgot the 'id' at the beginning of the line. So, after adding that I get a new warning: WARNING: Wrong input format: id 242856.60 431305.07 242551.88 432149.70 WARNING: [1] input format errors The man page says: Nodes can be piped into the program from file or from stdin. The syntax is as follows: id start_point_category end_point_category or id start_point_x start_point_y end_point_x end_point_y Points specified by category must be exactly on network nodes, while, when specifying coordinates, the next node to a given coordinate pair is used. What I tried was to put the upstream easting upstream northing downstream easting downstream northing as the points. What should the syntax be? Rich ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Calculating Length Between Points On Stream Network
On Sat, 27 Feb 2010, Dylan Beaudette wrote: Try the v.net.* modules. Dylan, I must be missing something. I put the e/n coordinates for the upstream/downstream points along the stream into a file called 'nodes'. Than I ran: GRASS 6.4.0svn (oregonM):/usr4/grassbase > v.net.path --o in=abernethy_creek out=stream_length type=line < nodes and saw this warning: WARNING: Point 242551.88,432149.70 is not reachable from point 0.60,431305.07 WARNING: 1 destination(s) unreachable (including points out of threshold) Here is the contents of 'nodes': 242856.60 431305.07 242551.88 432149.70 Any idea what I've done incorrectly? Those points are on the stream itself on the map. Thanks, Rich ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Calculating Length Between Points On Stream Network
Hi Richard, Try the v.net.* modules. Cheers, Dylan On Sat, Feb 27, 2010 at 11:09 AM, Rich Shepard wrote: > I have a vector map of a stream network and want to find the distance > between two points on the main stem. I have the geographic coordinates of > each point on the line representing the stream. I tried v.what but I'm not > comfortable that gave me the correct answer. > > The line between the two points is multiple segments where there are > confluences with feeder streams. > > What module, used with the GUI or on the command line, will allow me to > calculate the distance along the stream between two identified points? > > Rich > ___ > grass-user mailing list > grass-user@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/grass-user > ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] ps.map: Error Using Fill Patterns
Hamish wrote: > so r_vareas.c scans the filename string for $GISBASE and expands it to > G_gisbase() if needed. For some reason in yours it gets past that > expansion somehow. That feature is in 6.5 and 7.0 but not in 6.4. -- Glynn Clements ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] ps.map: Error Using Fill Patterns
On Sat, 27 Feb 2010, Hamish wrote: (no idea) Hamish, I suspect this is the result of the same issue: file location. I'll replace $GISBASE with the actual path and see if that makes a difference. Thanks, Rich ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] Calculating Length Between Points On Stream Network
I have a vector map of a stream network and want to find the distance between two points on the main stem. I have the geographic coordinates of each point on the line representing the stream. I tried v.what but I'm not comfortable that gave me the correct answer. The line between the two points is multiple segments where there are confluences with feeder streams. What module, used with the GUI or on the command line, will allow me to calculate the distance along the stream between two identified points? Rich ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] ps.map: Error Using Fill Patterns
On Fri, 26 Feb 2010, Hamish wrote: I'm not sure why but the quick fix is to just spell out the full path to the file and not use the variable. Hamish, Thank you. That's what I'll do. Rich ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] change location and mapset in the grass command line
2010/2/27 Markus Neteler > On Sat, Feb 27, 2010 at 11:43 AM, maven apache > wrote: > > Thanks > > > > Does the gisrc file (.grassrc6) work for just one user? I mean if more > than > > one user use the grass , should I create a .grassrc6 which contain a new > > location and mapset for each user? > > Are they real or Web users? > Perhaps take a look at > http://grass.osgeo.org/wiki/Parallel_GRASS_jobs > > Markus > Web users, they call the grass installed in the server to do some geo-process, they may call it at the same time. ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] change location and mapset in the grass command line
On Sat, Feb 27, 2010 at 11:43 AM, maven apache wrote: > Thanks > > Does the gisrc file (.grassrc6) work for just one user? I mean if more than > one user use the grass , should I create a .grassrc6 which contain a new > location and mapset for each user? Are they real or Web users? Perhaps take a look at http://grass.osgeo.org/wiki/Parallel_GRASS_jobs Markus ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] change location and mapset in the grass command line
Thanks Does the gisrc file (.grassrc6) work for just one user? I mean if more than one user use the grass , should I create a .grassrc6 which contain a new location and mapset for each user? ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] ps.map: Error Using Fill Patterns
Rich Shepard wrote: > In an input file to ps.map I have a vareas section with this: > > vareas house_basin > pat $GISBASE/etc/paint/patterns/diag_down6.eps > fcolor magenta > end > > The module runs, but when I try to display the map > using gv I get the > raster displayed, but no vector maps. The following error > is displayed in a separate window: > > Error: /rangecheck in --makepattern-- > Operand stack: >--dict:7/7(L)-- --nostringval-- false --dict:7/8(L)-- > --nostringval-- > Execution stack: >%interp_exit .runexec2 --nostringval-- --nostringval-- > --nostringval-- 2 %stopped_push --nostringval-- --nostringval-- > --nostringval-- false 1 %stopped_push 1905 1 3 %oparray_pop > 1904 1 3 %oparray_pop 1888 1 3 %oparray_pop 1771 1 3 > %oparray_pop --nostringval-- %errorexec_pop .runexec2 > --nostringval-- --nostringval-- --nostringval-- 2 %stopped_push > --nostringval-- 1854 2 3 %oparray_pop --nostringval-- > Dictionary stack: >--dict:1156/1684(ro)(G)-- --dict:0/20(G)-- --dict:115/200(L)-- > Current allocation mode is local > Last OS error: 2 > Current file position is 62506913 > GPL Ghostscript 8.63: Unrecoverable error, exit code 1 > > Ideas appreciated in how to resolve this. (no idea) does ps2ps help? does removing that vareas instruction help? does using a different or no pattern help? any hints in the module output? Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] change location and mapset in the grass command line
maven apache wrote: > I want to know if I can change my the grass location in the > command line? > > I know the g.mapsets command to change mapset,how about the > location? g.mapset location= (no "s") do so at your own risk though, check that temporary files are removed and you probably don't want to have the GUI running. if possible it is much cleaner to exit grass and restart in the new location. Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] change location and mapset in the grass command line
Hi: I want to know if I can change my the grass location in the command line? I know the g.mapsets command to change mapset,how about the location? ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
