[GRASS-user] v.to.rast Converted points/lines: 0 of 47763
Hi, today another question. My problem: I converted boundaries from an area vmap to lines via v.type v.type input=git...@achim output=gitter_lines type=boundary,line --o Now I want to convert these lines to raster-cells via: v.to.rast --overwrite input=gitter_li...@achim output=gitter_lines use=cat type=line but nothing converts! Loading data... Pass 1 of 2: Reading features... Schreibe Rasterkarte... Pass 2 of 2: Schreibe Rasterkarte... Converted areas: 0 of 0 Converted points/lines: 0 of 47763 v.to.rast komplett. What am I doing wrong? thanks, achim ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] v.to.rast Converted points/lines: 0 of 47763
achim wrote: today another question. My problem: I converted boundaries from an area vmap to lines via v.type v.type input=git...@achim output=gitter_lines type=boundary,line --o Now I want to convert these lines to raster-cells via: v.to.rast --overwrite input=gitter_li...@achim output=gitter_lines use=cat type=line but nothing converts! Loading data... Pass 1 of 2: Reading features... Schreibe Rasterkarte... Pass 2 of 2: Schreibe Rasterkarte... Converted areas: 0 of 0 Converted points/lines: 0 of 47763 v.to.rast komplett. What am I doing wrong? boundaries typically do not have a category value (e.g. a boundary between two fields: which farmer owns the boundary?), but sometimes can (e.g. if boundary is also a road) only items with category are processed by most vector modules (they loop from the first cat to the last cat). So run v.category to add cats to your lines and then it should work. there is a (short) word about this in the vectorintro help file. Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] v.to.rast Converted points/lines: 0 of 47763
Thanks Hamish, but I do have cats. I did v.clean and I tried with v.category, too. But it doesn't help. Maybe my cats addressing the nodes??? achim Hamish schrieb: achim wrote: today another question. My problem: I converted boundaries from an area vmap to lines via v.type v.type input=git...@achim output=gitter_lines type=boundary,line --o Now I want to convert these lines to raster-cells via: v.to.rast --overwrite input=gitter_li...@achim output=gitter_lines use=cat type=line but nothing converts! Loading data... Pass 1 of 2: Reading features... Schreibe Rasterkarte... Pass 2 of 2: Schreibe Rasterkarte... Converted areas: 0 of 0 Converted points/lines: 0 of 47763 v.to.rast komplett. What am I doing wrong? boundaries typically do not have a category value (e.g. a boundary between two fields: which farmer owns the boundary?), but sometimes can (e.g. if boundary is also a road) only items with category are processed by most vector modules (they loop from the first cat to the last cat). So run v.category to add cats to your lines and then it should work. there is a (short) word about this in the vectorintro help file. Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] v.to.rast Converted points/lines: 0 of 47763
Hi all, I solved by adding cat via v.category (only) for the lines. Before only centroids cats where present by default. v.clean not nesessary. Thanks Hamish! achim achim schrieb: Thanks Hamish, but I do have cats. I did v.clean and I tried with v.category, too. But it doesn't help. Maybe my cats addressing the nodes??? achim Hamish schrieb: achim wrote: today another question. My problem: I converted boundaries from an area vmap to lines via v.type v.type input=git...@achim output=gitter_lines type=boundary,line --o Now I want to convert these lines to raster-cells via: v.to.rast --overwrite input=gitter_li...@achim output=gitter_lines use=cat type=line but nothing converts! Loading data... Pass 1 of 2: Reading features... Schreibe Rasterkarte... Pass 2 of 2: Schreibe Rasterkarte... Converted areas: 0 of 0 Converted points/lines: 0 of 47763 v.to.rast komplett. What am I doing wrong? boundaries typically do not have a category value (e.g. a boundary between two fields: which farmer owns the boundary?), but sometimes can (e.g. if boundary is also a road) only items with category are processed by most vector modules (they loop from the first cat to the last cat). So run v.category to add cats to your lines and then it should work. there is a (short) word about this in the vectorintro help file. Hamish ___ 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] Testing i.pca ~ prcomp(), m.eigensystem ~ princomp()
Nikos: Finally all is clear _but_ one thing: the only unknown variable (to me) is still the Eigenvalue provided by i.pca. I can't nail this one: *** how is it calculated? *** Looks like it is some _weighted_ variance... !?? Hamish, if you have the time (or anyone , could you please translate the code in grass6_dev/imagery/i.pca/main.c, concerning the eigval variable, in some pseudocode. It is really the last thing to clarify ( I think ). I don't really have the time, I am just about to leave the office for a few weeks. but quickly: for i.pca they are calculated by the eigen() function in lib/gmath/eigen.c see also lib/gmath/eigen_tools.c unfortunately the programmer decided to use all one letter variables there and no comments.. but maybe the math is clear enough to tell which method is used. it will be really good to finally have all this documented. Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-stats] Re: [GRASS-user] Testing i.pca ~ prcomp(), m.eigensystem ~ princomp()
On Tue, Mar 3, 2009 at 12:26 PM, Hamish hamis...@yahoo.com wrote: ... it will be really good to finally have all this documented. I find it hard to follow these long mails. Why not enjoying the GRASS Wiki to stabilize the documentation and comparisons? Markus ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-stats] Re: [GRASS-user] Testing i.pca ~ prcomp(), m.eigensystem ~ princomp()
On Tue, 2009-03-03 at 13:18 +0100, Markus Neteler wrote: On Tue, Mar 3, 2009 at 12:26 PM, Hamish hamis...@yahoo.com wrote: ... it will be really good to finally have all this documented. I find it hard to follow these long mails. Why not enjoying the GRASS Wiki to stabilize the documentation and comparisons? Markus Yes, why not? Hmmm, you mean to put these stuff already in the Wiki before we are sure about the one last and very important variable (=eigenvalues reported by i.pca)? Kind regards, Nikos ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Testing i.pca ~ prcomp(), m.eigensystem ~ princomp()
Nikos: Eigenvalue provided by i.pca. I can't nail this one: *** how is it calculated? *** Looks like it is some _weighted_ variance... !?? Hamish, if you have the time (or anyone , could you please translate the code in grass6_dev/imagery/i.pca/main.c, concerning the eigval variable, in some pseudocode. It is really the last thing to clarify ( I think ). Hamish: for i.pca they are calculated by the eigen() function in lib/gmath/eigen.c see also lib/gmath/eigen_tools.c I am trying to get a grip on eigen.c. The variables that refer to the eigenvalues are symbolised as: double *lambda OR lambda which is the double d[] as defined IN G_tqli() IN eigen_tools.c And then there is this fabs in the way :-) I suppose it returns the absolute value of a signed number... It took me so long to figure this simple thing out. Well, there are so many variables... it's hard(=time-consuming) for the unexperienced eye to trace down the real math. As suggested by Markus, I will try to move this in the Wiki. Apologies for the long posts again, Nikos ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] r.water.outlet and SELECT WHERE Maximum
Hello, today I have two questions... No 1. r.water.outlet doesn't produce the hole outlet. I chose coordinates E and N from point coordinates. The point was converted from a raster-cell via r.to.vect. For illustration I attach a screenshot. No 2. I'd like to select the raster-cell with the highest value. I converted the raster to points and tried to select with SELECT WHERE. How can I use an maximum-statement in it? I couldn't fix it out. Or is there another way? (I use the default db) Best regards, achim inline: wateroutlet.jpg___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] about GRASS digitizer
dear grass user, I am new in grass using windows native GRASS GIS 6.3.0.4 and i am having problem to digitize a map. I will be very gratefull if you could help us. *Problem* * * A model map is as example for my problem. Ø My first step I have digitized the polygon *dhk* (showed in attached picture). Ø Now I have split two points and add node. Then I have drawn polygon of *khl.* Ø Then I have added centroid . It is not regioning with the polygon. Ø I have tried same problem with QGIS with grass extention. There after digitizing a simple polygon as shown picture e.g *dhk .* Is my procedure is correct ? I am little confused with the digitizing tool though I have read the manuals. Best zahid attachment: mymap_12k.JPG___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] about GRASS digitizer
Hello: Zahid Parvez wrote: dear grass user, I am new in grass using windows native GRASS GIS 6.3.0.4 and i am having problem to digitize a map. I will be very gratefull if you could help us. Problem A model map is as example for my problem. Ø My first step I have digitized the polygon dhk (showed in attached picture). Ø Now I have split two points and add node. Then I have drawn polygon of khl. Ø Then I have added centroid . It is not regioning with the polygon. Ø I have tried same problem with QGIS with grass extention. There after digitizing a simple polygon as shown picture e.g dhk . I'm not quite clear what your problem is. What do you mean "not regioning with the polygon" ? But perhaps this might help: http://grass.osgeo.org/wiki/Digitizing_Area_Features Regards, Micha Is my procedure is correct ? I am little confused with the digitizing tool though I have read the manuals. Best zahid ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] r.water.outlet and SELECT WHERE Maximum
Hi, achim píše v Út 03. 03. 2009 v 17:52 +0100: Hello, today I have two questions... No 1. r.water.outlet doesn't produce the hole outlet. I chose coordinates E and N from point coordinates. The point was converted from a raster-cell via r.to.vect. For illustration I attach a screenshot. IMHO, this is caused by rough raster resolution. You have to click to some other place in order to get outlet you ar looking for No 2. I'd like to select the raster-cell with the highest value. I converted the raster to points and tried to select with SELECT WHERE. How can I use an maximum-statement in it? I couldn't fix it out. Or is there another way? (I use the default db) something like SELECT cat FROM points WHERE z = (SELECT max(z) FROM points); However, I'm afraid, this is not possible with DBF driver, you'll have to convert the database e.g. into postgresql or sqlite j -- Jachym Cepicky e-mail: jachym.cepicky gmail com URL: http://les-ejk.cz GPG: http://les-ejk.cz/pgp/JachymCepicky.pgp ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
