Re: [GRASS-user] snap point to line/break line at given points
Am 16.04.2011 um 17:25 schrieb Daniel Victoria: Not sure how to split and label the rivers but to snap the point to the closest river you could use v.distance I also thought about v.distance. There I get the coordinates of the closest points on the new line (stdout). I just have to create a new pointfile from the standard output coordinates...or is there any simpler way? And I also still don't know how to split the lines at these points. I thought about v.split but here are segemnts created at equidistant breakpoints and one can only set the distance in metres but it is not possible to use coordinates as input...anyone knows how to do that? cheers /johannes Cheers daniel http://grass.fbk.eu/grass65/manuals/html65_user/v.distance.html On Thu, Apr 14, 2011 at 6:36 AM, Johannes Radinger wrote: Hello, I have a line-vector (river) and some points on that line. First I am straightening that line with v.generalize (method: boyle). Now, there is the problem that the points are not exactly on the line anymore. So I want to snap (move) the points to the new generalized line again. Which tool is able to do that? After that I want to split the line at these points and want to give the attribute value to the newly created segments. These segment values should represent the number/value of the upstream point (which was used to split). How can this be done in GRASS? Do you have any ideas to solve these two problems/challenges? thank you /johannes -- GMX DSL Doppel-Flat ab 19,99 Euro/mtl.! Jetzt mit gratis Handy-Flat! http://portal.gmx.net/de/go/dsl ___ 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
[GRASS-user] Importing shp files...setting up new location
I have spearfish60 up and running but now I want to set up a locations housing some of my vector and raster filesand most will have to be imported. When you drill down to subdirectories...do you put all shp files in a vector directory and all raster in a raster directory first or do you run the import routines and do these routines populate the aforementioned subdirectories or are they stored elsewhere? Michael D. Morin mmo...@cassblue.com ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] river profile, how to
If you have the shapefile for the river (or vector line in GRASS) you can convert it to points by using v.to.points and making the points really close to one another (make dmax small). then use *v.what.rast* to get the elevation at the points locations. Hope it helps On Sun, Apr 17, 2011 at 8:18 AM, ambijat wrote: > Hi All, > I wish to develop a river profile from start point to its last. The GRASS > 6.4.1 has a tool profile analysis, which is a bit crude. If I take two > points, eg. river head and its last point then it gives a profile, but it is > a direct and not along the course of the river. And, if I create a series of > point all along the course, then certainly not the best values are there as > selection process is very tedious. So, is there a method which would > automatically take the raster values of the river course seen as a line and > give a simple fine river profile. > > Thanks > > Ambrish Dhaka > ___ > 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
[GRASS-user] Display fixed
Thanks to all who provided comments about my 'Display' problem. Seems more frameworks needed to be loaded. Michael D. Morin mmo...@cassblue.com ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] assign heigght value to pixel(x,y)
Hi, i'm not sure that the raster way is the easiest, the tools are not really usable for what you want to do ... you better have to make a new vector layer with a "height" attribute, then display it over your raster and edit the vector layer by drawing polygon/point with the height as attibute. Once ended, you will have to convert the vector to raster (v.to.rast) using the attribute "height" as raster value. I think it's the easiest way as you will be able to store the same height for many consecutive pixel without having to edit each one, and you will also be able to easily change the height if your first try is not good enought ;) cheers, Sylvain 2011/4/17 vinod kumar > Hi Markus Netler, > > i want to identify buildings, trees etc.. and assign height values at > particular zoom level in a raster map and to view the data in a 3Dimensional > where i do not have any information to identify pixel graphically. > > And the problem also persists in identifying buildings and assigning height > values and to use condition like IF might not be possible as there is no > source of information. > > Thanks in advance, > nani. > > > > On Sat, Apr 16, 2011 at 11:06 PM, Markus Neteler wrote: > >> On Sat, Apr 16, 2011 at 10:36 PM, vinod kumar >> wrote: >> > Hi Markus Neteler, >> > >> > yes, importing pixel values with r.in ascii and patch into existing >> into >> > raster is simple easy for particular pixel, >> > but if we want to assign a height value to more pixels, for example >> > assigning height value to buildings in a >> > particular area in raster map is difficult as we don't no to which pixel >> > value we have to assign height value and >> > checking each pixel value is difficult. >> >> Now I understand a bit more: so use r.mapcalc with an if() condition. >> >> Markus >> > > > ___ > 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] assign heigght value to pixel(x,y)
Hi Markus Netler, i want to identify buildings, trees etc.. and assign height values at particular zoom level in a raster map and to view the data in a 3Dimensional where i do not have any information to identify pixel graphically. And the problem also persists in identifying buildings and assigning height values and to use condition like IF might not be possible as there is no source of information. Thanks in advance, nani. On Sat, Apr 16, 2011 at 11:06 PM, Markus Neteler wrote: > On Sat, Apr 16, 2011 at 10:36 PM, vinod kumar > wrote: > > Hi Markus Neteler, > > > > yes, importing pixel values with r.in ascii and patch into existing into > > raster is simple easy for particular pixel, > > but if we want to assign a height value to more pixels, for example > > assigning height value to buildings in a > > particular area in raster map is difficult as we don't no to which pixel > > value we have to assign height value and > > checking each pixel value is difficult. > > Now I understand a bit more: so use r.mapcalc with an if() condition. > > Markus > ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] Applying Algorithm
Hi All, I am having algorithm or psuedo code(consists of initialisation of parameters, conditions, comparing, etc.. ) of a program. how to execute these set of statements in Grass. Give me an example Thanks in advance, nani. ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] assign heigght value to pixel(x,y)
Hi Markus Netler, Using r.mapcalc with an if() condition might work but how can we give a condition without knowing anything about pixels(like.. where it is located and height.. etc). i am doing this for to assign height values to some pixels where i do not know the buildings location in a raster map graphically. I think we are on the way to the solution. next step would be the solution. thanks, nani. On Sun, Apr 17, 2011 at 8:06 AM, Markus Neteler wrote: > On Sat, Apr 16, 2011 at 10:36 PM, vinod kumar > wrote: > > Hi Markus Neteler, > > > > yes, importing pixel values with r.in ascii and patch into existing into > > raster is simple easy for particular pixel, > > but if we want to assign a height value to more pixels, for example > > assigning height value to buildings in a > > particular area in raster map is difficult as we don't no to which pixel > > value we have to assign height value and > > checking each pixel value is difficult. > > Now I understand a bit more: so use r.mapcalc with an if() condition. > > Markus > ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] river profile, how to
Hi All, I wish to develop a river profile from start point to its last. The GRASS 6.4.1 has a tool profile analysis, which is a bit crude. If I take two points, eg. river head and its last point then it gives a profile, but it is a direct and not along the course of the river. And, if I create a series of point all along the course, then certainly not the best values are there as selection process is very tedious. So, is there a method which would automatically take the raster values of the river course seen as a line and give a simple fine river profile. Thanks Ambrish Dhaka ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Loaded Spearfish...no display?
Hi, 2011/4/16 Michael Morin 'zoom to selected map' (right click on map layer in layer tree) doesn't work? No error is command output? Martin -- Martin Landa * http://geo.fsv.cvut.cz/~landa ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
