Re: [GRASS-user] Fwd: How to obtain selected adjacent pixel values?
(cc-ing @MarkusMetz) Yasser Said Lopez de Olmos Reyes wrote: How could I obtain the differences between central pixel values and cardinal directions pixel values related with a central pixel? Or in a different manner, how to do this in grass gis? RASTER_OUT= round(abs((RASTER_IN - RASTER_IN_PUSHED_ONE_ROW_UP) + (RASTER_IN - RASTER_IN_PUSHED_ONE_ROW_DOWN) + (RASTER_IN - RASTER_IN_PUSHED_ONE_COLUMN_LEFT) + (RASTER_IN - RASTER_IN_PUSHED_ONE_COLUMN_RIGHT)) Nikos Alexandris wrote: This boils down to calculating (RASTER_IN - RASTER_IN_PUSHED_ONE_ROW_UP) + (RASTER_IN - RASTER_IN_PUSHED_ONE_ROW_DOWN) + (RASTER_IN - RASTER_IN_PUSHED_ONE_COLUMN_LEFT) + (RASTER_IN - RASTER_IN_PUSHED_ONE_COLUMN_RIGHT) Please check the manual of r.mapcalc. There is --%--- THE NEIGHBORHOOD MODIFIER .. ---%-- which I think can be used to obtain what is asked. So, for each of the off-current pixel, the modifiers would be like RASTER_IN_PUSHED_ONE_ROW_UP: map[-1,0] RASTER_IN_PUSHED_ONE_ROW_DOWN: map[1,0] RASTER_IN_PUSHED_ONE_COLUMN_LEFT: map[0,-1] RASTER_IN_PUSHED_ONE_COLUMN_RIGHT: map[0,1] I am not exactly sure about the implementation though. @Yasser, if you implement this and think it is something that can be justified as generically useful, why not ask @MarkusMetz if it is easy to include in r.neighbors as yet another method? Best, Nikos ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] grass prompt default working directory
Nikos wrote: Luckily, the history functions of bash are very handy (e.g. Ctrl + R and more). Hamish: re. and more, fwiw, I find adding this to ~/.inputrc is much nicer to use than ^r, # Bind page up/down wih history search - \e[5~: history-search-backward \e[6~: history-search-forward type the first few letters, then PgUp to see earlier matches.. [..] still, it does not replace continuous Ctrl+R which will go through _all_ matches of the typed string, initially earlier lines starting with it, then through the entire history, no matter where the given string is located in a recorder command. I think I can't do without the PgUp trick in the terminal. Sometime I still use Ctrl+R :-). And, if I am not wrong, it's by default in openSUSE (12.3?) -- I didn't edit anything and it was already working! Thanks Hamish, N ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] TO BE POST: Extract a smaller image (sample) from a raster map
COULD THIS BE POSTED TO THE MAILING LIST, PLEASE? I'M SUBSCRIBED TO IT BUT MY POST APPEAR AS ... NOT been accepted by the mailing list yet. Hi everyone: Have Modis images MOD13Q1 reprojected into Tiff format imported into grass to analize NDVI for different months and seasons. As I just need to analize NDVI for a specific crop area of the image imported, I want to extract or select that region from the raster map. After reading several post explaining that R.region/G.region should be use to set the geographic boundaries, I decided to follow the instruction and have use r.region setting nort, south, east and west values of the smaller area BUT only get the same image narrower in width and longer in high. Now, when I follow the use of this command again I get the message unable to parse command r.region I'm new in Grass! and feel confuse. What I am missing? Please help! Many Thanks in adavance. ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] TO BE POST: Extract a smaller image (sample) from a raster map
Liria Boix wrote: Hi everyone: Hello Liria, Have Modis images MOD13Q1 reprojected into Tiff format imported into grass to analize NDVI for different months and seasons. As I just need to analize NDVI for a specific crop area of the image imported, I want to extract or select that region from the raster map. You need to use g.region to set the computational region, that is the extent to which (almost) all grass raster modules will operate on. After reading several post explaining that R.region/G.region should be use to set the geographic boundaries, The r.region module will define/modify the boundaries of the image itself, not the extent where the raster operations will take place. This module is useful, for example, in case the extent or the placement of a raster map is not the one it should be/the user wants it to be. I decided to follow the instruction and have use r.region setting nort, south, east and west values of the smaller area BUT only get the same image narrower in width and longer in high. You need to use g.region. Now, when I follow the use of this command again I get the message unable to parse command r.region I'm new in Grass! and feel confuse. What I am missing? Please help! Many Thanks in adavance. Please have a quick-read through the following useful material: - http://grass.osgeo.org/grass64/manuals/rasterintro.html - http://grass.osgeo.org/grass64/manuals/imageryintro.html There are several references upon r.region and g.region. Best, Nikos ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] Extract a smaller image (sample) from a raster map
Many thanks for the explanation! I read the links you have posted and others like specific to r.region and g.region, still a bit confuse with some concepts. HOWEVER, still not able yet to extract a smaller image from the bigger one!. Have used *g.region* setting the values of a smaller area, and have set it as computational region but the image displayed is the same. I did the same importing a new image and setting r.region but not getting any difference! Feel a little bit frustrated -- View this message in context: http://osgeo-org.1560.x6.nabble.com/Extract-a-smaller-image-sample-from-a-raster-map-tp5063094p5063102.html Sent from the Grass - Users mailing list archive at Nabble.com. ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Fwd: How to obtain selected adjacent pixel values?
On Sun, Jun 30, 2013 at 3:31 PM, Nikos Alexandris n...@nikosalexandris.net wrote: (cc-ing @MarkusMetz) Yasser Said Lopez de Olmos Reyes wrote: How could I obtain the differences between central pixel values and cardinal directions pixel values related with a central pixel? Or in a different manner, how to do this in grass gis? RASTER_OUT= round(abs((RASTER_IN - RASTER_IN_PUSHED_ONE_ROW_UP) + (RASTER_IN - RASTER_IN_PUSHED_ONE_ROW_DOWN) + (RASTER_IN - RASTER_IN_PUSHED_ONE_COLUMN_LEFT) + (RASTER_IN - RASTER_IN_PUSHED_ONE_COLUMN_RIGHT)) Nikos Alexandris wrote: This boils down to calculating (RASTER_IN - RASTER_IN_PUSHED_ONE_ROW_UP) + (RASTER_IN - RASTER_IN_PUSHED_ONE_ROW_DOWN) + (RASTER_IN - RASTER_IN_PUSHED_ONE_COLUMN_LEFT) + (RASTER_IN - RASTER_IN_PUSHED_ONE_COLUMN_RIGHT) Please check the manual of r.mapcalc. There is --%--- THE NEIGHBORHOOD MODIFIER .. ---%-- which I think can be used to obtain what is asked. So, for each of the off-current pixel, the modifiers would be like RASTER_IN_PUSHED_ONE_ROW_UP: map[-1,0] RASTER_IN_PUSHED_ONE_ROW_DOWN: map[1,0] RASTER_IN_PUSHED_ONE_COLUMN_LEFT: map[0,-1] RASTER_IN_PUSHED_ONE_COLUMN_RIGHT: map[0,1] I am not exactly sure about the implementation though. r.mapcalc RASTER_OUT=round(abs((RASTER_IN - RASTER_IN[0,-1]) + \ (RASTER_IN - RASTER_IN[0,1]) + \ (RASTER_IN - RASTER_IN[-1,0]) + \ (RASTER_IN - RASTER_IN[1,0]))) Note that this is the same like round(abs(4 * RASTER_IN - (RASTER_IN[0,-1] + RASTER_IN[0,1] + RASTER_IN[-1,0] + RASTER_IN[1,0]))) If you are interested in the sum of the absolute differences, you will need to use abs() for each difference. @Yasser, if you implement this and think it is something that can be justified as generically useful, why not ask @MarkusMetz if it is easy to include in r.neighbors as yet another method? # prepare a weights file with the contents 0 1 0 1 0 1 0 1 0 r.neighbors in=raster_in out=raster_cardinalsum weight=weights method=sum r.mapcalc RASTER_OUT = round(abs(4 * RASTER_IN - raster_cardinalsum)) HTH, Markus M ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Fwd: How to obtain selected adjacent pixel values?
Sorry, I just need to tell you I'm gonna work on this next week, but I really don't want to discourage you waiting with no news. Thank you all. 2013/6/30 Markus Metz markus.metz.gisw...@gmail.com On Sun, Jun 30, 2013 at 3:31 PM, Nikos Alexandris n...@nikosalexandris.net wrote: (cc-ing @MarkusMetz) Yasser Said Lopez de Olmos Reyes wrote: How could I obtain the differences between central pixel values and cardinal directions pixel values related with a central pixel? Or in a different manner, how to do this in grass gis? RASTER_OUT= round(abs((RASTER_IN - RASTER_IN_PUSHED_ONE_ROW_UP) + (RASTER_IN - RASTER_IN_PUSHED_ONE_ROW_DOWN) + (RASTER_IN - RASTER_IN_PUSHED_ONE_COLUMN_LEFT) + (RASTER_IN - RASTER_IN_PUSHED_ONE_COLUMN_RIGHT)) Nikos Alexandris wrote: This boils down to calculating (RASTER_IN - RASTER_IN_PUSHED_ONE_ROW_UP) + (RASTER_IN - RASTER_IN_PUSHED_ONE_ROW_DOWN) + (RASTER_IN - RASTER_IN_PUSHED_ONE_COLUMN_LEFT) + (RASTER_IN - RASTER_IN_PUSHED_ONE_COLUMN_RIGHT) Please check the manual of r.mapcalc. There is --%--- THE NEIGHBORHOOD MODIFIER .. ---%-- which I think can be used to obtain what is asked. So, for each of the off-current pixel, the modifiers would be like RASTER_IN_PUSHED_ONE_ROW_UP: map[-1,0] RASTER_IN_PUSHED_ONE_ROW_DOWN: map[1,0] RASTER_IN_PUSHED_ONE_COLUMN_LEFT: map[0,-1] RASTER_IN_PUSHED_ONE_COLUMN_RIGHT: map[0,1] I am not exactly sure about the implementation though. r.mapcalc RASTER_OUT=round(abs((RASTER_IN - RASTER_IN[0,-1]) + \ (RASTER_IN - RASTER_IN[0,1]) + \ (RASTER_IN - RASTER_IN[-1,0]) + \ (RASTER_IN - RASTER_IN[1,0]))) Note that this is the same like round(abs(4 * RASTER_IN - (RASTER_IN[0,-1] + RASTER_IN[0,1] + RASTER_IN[-1,0] + RASTER_IN[1,0]))) If you are interested in the sum of the absolute differences, you will need to use abs() for each difference. @Yasser, if you implement this and think it is something that can be justified as generically useful, why not ask @MarkusMetz if it is easy to include in r.neighbors as yet another method? # prepare a weights file with the contents 0 1 0 1 0 1 0 1 0 r.neighbors in=raster_in out=raster_cardinalsum weight=weights method=sum r.mapcalc RASTER_OUT = round(abs(4 * RASTER_IN - raster_cardinalsum)) HTH, Markus M -- Saludos, Yasser ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Extract a smaller image (sample) from a raster map
Lbxa wrote: Many thanks for the explanation! (Thanks to the guys spending nights to code all that stuff...) I read the links you have posted and others like specific to r.region and g.region, still a bit confuse with some concepts. HOWEVER, still not able yet to extract a smaller image from the bigger one!. Have used *g.region* setting the values of a smaller area, and have set it as computational region but the image displayed is the same. I did the same importing a new image and setting r.region but not getting any difference! Feel a little bit frustrated (No pain, no Gain :-p). So, one step at a time, and assuming you have created a Location based on the Spatial Reference System in which your data are defined/projected: 1. import raster map(s) using r.in.gdal -- nothing else required (no r.region required unless something is wrong with the imported data) 2. set the computational region using g.region, e.g. - g.region rast=YourRastMap will set the computational region to match the extent of your raster map (which is _not_ what you are after, if I got it right) - g.region w= e= s= n= to set a custom defined computational region 3. r.mapcalc Test = YourRasterMap -- this will simply copy YourRasterMap, yet, only for inside the computational region! Hope this helps a bit, Nikos ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Fwd: How to obtain selected adjacent pixel values?
[..] Markus Metz wrote: # prepare a weights file with the contents 0 1 0 1 0 1 0 1 0 r.neighbors in=raster_in out=raster_cardinalsum weight=weights method=sum r.mapcalc RASTER_OUT = round(abs(4 * RASTER_IN - raster_cardinalsum)) ...easy, it is, to build a filter in GRASS :D Thanks Markus, N ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] version 6.4.3 and mysql
Hello, I have a question about Version 6.4.3 for Windows 7. Is there a way to access MySql databases from within the software? I don't see it listed as one of the drivers in the GUI, but am hoping there is a means by which to connect and retrieve or update data. Thank you very much for your time and consideration. Sincerely, Mike Mavis___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] version 6.4.3 and mysql
Mike wrote: I have a question about Version 6.4.3 for Windows 7. Is there a way to access MySql databases from within the software? I don't see it listed as one of the drivers in the GUI, but am hoping there is a means by which to connect and retrieve or update data. Hi, looking at 'g.version -b' there it seems that the Windows installer was not built with MySql support. (Sqlite, PostgreSQL, DBF, and ODBC are there) I don't think there's any big reason for it not being there except that the packager didn't add that option when they were building it. (it's a bit more that just adding the --with-mysql switch in the configuration, we also have to build and ship the needed mysql libraries) I'm not sure how much extra work it would be to add it, but it's just a matter of rebuilding the package as far as I know. If you are familiar with that sort of thing all the instructions are on the wiki and build scripts in the tools directory our addons repo- sitory and mswindows/ directory in the main source code. It relies on the osgeo4w build infrastructure, http://trac.osgeo.org/osgeo4w/ Otherwise please feel free to file a wish ticket in the trac system, and hopefully someone with talents in the area can enable it for you. I think MySql on Windows is a pretty common combination, so it sounds like a reasonable request to me. For now you might see if you can communicate with mysql through the common ODBC driver? regards, Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Extract a smaller image (sample) from a raster map
Nikos wrote: 2. set the computational region using g.region, e.g. - g.region rast=YourRastMap will set the computational region to match the extent of your raster map (which is _not_ what you are after, if I got it right) - g.region w= e= s= n= to set a custom defined computational region just a little side note, at this point in the process it is always good to check the computational region result with 'g.region -p', if the bounds and or resolution got messy you can fix it with the 'g.region align=original_map' command, or 'g.region -a res=...' at the chosen resolution. also, if you changed anything with r.region it is probably best to delete the first attempt and re-import the map from the raw file. Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
