Re: [GRASS-user] Re: Importing Dems with r.in.xyz
2010/6/5, Hamish hamis...@yahoo.com: Hanlie wrote: At this point, g.region reports 1146474 cells in the region, while I have 1146370 lines of coordinates in my file. ... So it looks like there are about 100 coordinates missing from the ASCII ASCII file. 0.01% .. Maybe holes in the data? perhaps this: https://trac.osgeo.org/grass/ticket/123 ?? I don't think it's this bug because this bug discards only one line of data. I don't get any data in because the number of coordinate pairs in the file is less than the number of cells in the defined region. I was thinking perhaps importing the points as vectors, converting them to raster and then doing a nearest neighbour or IDW interpolation to fill the gaps. At least then I'll be able to see where the gaps are and limit the interpolated pixels using a mask? No need to do anything different to find the missing pixels. Inspecting the output of r.univar with r.in.xyz's method=n maps can be very useful for troubleshooting. from the help page: Gridded data If data is known to be on a regular grid r.in.xyz can reconstruct the map perfectly as long as some care is taken to set up the region correctly and that the data's native map projection is used. A typical method would involve determining the grid resolution either by examining the data's associated documentation or by studying the text file. Next scan the data with r.in.xyz's -s (or -g) flag to find the input data's bounds. GRASS uses the cell-center raster convention where data points fall within the center of a cell, as opposed to the grid-node convention. Therefore you will need to grow the region out by half a cell in all directions beyond what the scan found in the file. After the region bounds and resolution are set cor- rectly with g.region, run r.in.xyz using the n method and verify that n=1 at all places. r.univar can help. Once you are confident that the region exactly matches the data proceed to run r.in.xyz using one of the mean, min, max, or median methods. With n=1 throughout, the result should be identical regardless of which of those methods are used. with the n map you might use r.mapcalc to extract the NULL cells as some value, then r.out.xyz or r.to.vect on th extracts to highlight where they are. Or maybe you get lucky with r.colors with nv set to bright magenta on the original data. Thanks, I'll try this to find where the holes in the data are. Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Re: Importing Dems with r.in.xyz
Hanlie Pretorius wrote: 2010/6/5, Hamish hamis...@yahoo.com: Hanlie wrote: At this point, g.region reports 1146474 cells in the region, while I have 1146370 lines of coordinates in my file. ... So it looks like there are about 100 coordinates missing from the ASCII ASCII file. 0.01% .. Maybe holes in the data? perhaps this: https://trac.osgeo.org/grass/ticket/123 ?? I don't think it's this bug because this bug discards only one line of data. I don't get any data in because the number of coordinate pairs in the file is less than the number of cells in the defined region. Weird. In 6.4, r.in.xyz does import a file where the number of coordinate pairs is far less than the number of cells in the defined region. (I just did a simple test with two input lines and a region with 26.5 million cells, got clean import and correct result) You can interpolate NULL cells and a the same time keep non NULL cell values with r.fillnulls. I would suggest to set the region to north: -49312.5 south: -74587.5 west: -3015862.5 east: -2987512.5 nsres: 25 ewres: 25 have clean 25m resolution for both ns and ew in order to make life easier. The 1cm difference in the last input lines you posted can not possibly make a difference with 25m point spacing and is most probably some floating point rounding error introduced by some preprocessing to generate the ascii xyz input file. HTH, Markus M I was thinking perhaps importing the points as vectors, converting them to raster and then doing a nearest neighbour or IDW interpolation to fill the gaps. At least then I'll be able to see where the gaps are and limit the interpolated pixels using a mask? No need to do anything different to find the missing pixels. Inspecting the output of r.univar with r.in.xyz's method=n maps can be very useful for troubleshooting. from the help page: Gridded data If data is known to be on a regular grid r.in.xyz can reconstruct the map perfectly as long as some care is taken to set up the region correctly and that the data's native map projection is used. A typical method would involve determining the grid resolution either by examining the data's associated documentation or by studying the text file. Next scan the data with r.in.xyz's -s (or -g) flag to find the input data's bounds. GRASS uses the cell-center raster convention where data points fall within the center of a cell, as opposed to the grid-node convention. Therefore you will need to grow the region out by half a cell in all directions beyond what the scan found in the file. After the region bounds and resolution are set cor- rectly with g.region, run r.in.xyz using the n method and verify that n=1 at all places. r.univar can help. Once you are confident that the region exactly matches the data proceed to run r.in.xyz using one of the mean, min, max, or median methods. With n=1 throughout, the result should be identical regardless of which of those methods are used. with the n map you might use r.mapcalc to extract the NULL cells as some value, then r.out.xyz or r.to.vect on th extracts to highlight where they are. Or maybe you get lucky with r.colors with nv set to bright magenta on the original data. Thanks, I'll try this to find where the holes in the data are. 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] Select random cells from map
Thanks Hamish I thought that random cells are retrieved from valid map cells. Or not? Antonio Hamish wrote: António wrote: I need to randomly select non-null cells from a given map. I tried r.random.cells but I cannot define a maximum number random cells and some selected random cells are not valid values in my map. is there any other function to randomly select cells from a raster? Hamish: r.to.vect to get a vector area coverage of your raster (do not use the -s flag), then v.random.cover from wiki addons then v.to.rast, and finally r.mapcalc to transfer values from source map to random cell map? (probably we/I should make a new wrapper script to do that automatically) or you might skip the last steps and just use v.random.cover's raster= option to sample the raster map directly. probably the best idea is to fix r.random's cover= option to loop until it has enough points. also if you will be doing a lot of geostats it is probably worth your while to learn about the GRASS-R interface: http://grass.osgeo.org/wiki/R_statistics ... then the world is open to you. António wrote: Thanks for your answer. I tried r.random with my input data and the number of cells and it worked but I do have one question: I didn't understand the objective of cover_map. I used the map from I want to extract random cells as input but what is the objective of cover_map? r.random creates random points all over the current rectangular region block. Adding a cover map makes those random points only occur within the irregular area covered by the cover map. (but r.random cover= is a bit buggy right now; see new ticket in the bug trac'er) Hamish __ Information from ESET NOD32 Antivirus, version of virus signature database 5177 (20100606) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __ Information from ESET NOD32 Antivirus, version of virus signature database 5178 (20100607) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Re: Importing Dems with r.in.xyz
Hanlie Pretorius wrote: I don't think it's this bug because this bug discards only one line of data. I don't get any data in because the number of coordinate pairs in the file is less than the number of cells in the defined region. Markus Metz: Weird. In 6.4, r.in.xyz does import a file where the number of coordinate pairs is far less than the number of cells in the defined region. (I just did a simple test with two input lines and a region with 26.5 million cells, got clean import and correct result) sorry, I'm not really grasping what the problem is. If you suspect there is something weird going on can you make the .xyz.bz2 file available for me to download, and supply the output of r.univar `wc -l` and `r.in.xyz --verbose`? Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Using Vector Digitizer in Windows
Where can I find that tab? I can't find it at TclTkDigitizer 2010/6/3 Hamish hamis...@yahoo.com Kim: How can I put an image as a background? I am at v.digit form and I cannot see any field regarding that Markus: There should be, when starting, the option to select a background display *command* http://grass.osgeo.org/grass64/manuals/html64_user/v.digit.html which could be set to d.rast map=name_of_raster also you can do it in the settings controls once in the tool, there's a tab for it. Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Georrectify and nearest neighbor
Hi Ok, but at least at georectify tool, Neares is used right? as well as copying a map from one mapset to another Regarding the link, there is no explanation regarding the tutorial video. I mean, step by step what I do have to do Thanks On Thu, Jun 3, 2010 at 10:59 PM, Markus Neteler nete...@osgeo.org wrote: On Wed, Jun 2, 2010 at 10:04 AM, Jenny Turner jennyturner1...@gmail.com wrote: My name is Jenny Turner and I've been using georrectify graphical module in WxpyTHon GRASS6.4. I saw a video of the proceeding but I would like to know if there is a description or a tutorial of what to do and how. Please take a look here: http://grass.osgeo.org/wiki/Georeferencing I have understand what I have to do but I need to explain to other persons (non-grass users :) ). Just one more thing: Is it used any resampling to the data or only nearest neighbor? Currently nearest neighbor. There may be a chance to have a choice in future in GRASS 7 to also use other methods. Please note that many resampling algorithms are already present in GRASS, just not yet integrated with the image processing part. Markus ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] r.in.gdal- renaming bands
Greetings I have a stack of images and when I import it to GRASS it starts to renaming as blue, green, red and then numbers. Why does it attribute those names since I'm not asking for it? Thank Katrin ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Using Vector Digitizer in Windows
On 07/06/2010 12:27, Kim Besson wrote: Where can I find that tab? I can't find it at TclTkDigitizer Once you start the digitizer, there's a button "Open Settings" (with colored stripes). In the setting window you'll see a tab Background. There you click "Add command" and type in a d.rast command to show some background. 2010/6/3 Hamish hamis...@yahoo.com Kim: How can I put an image as a background? I am at v.digit form and I cannot see any field regarding that Markus: There should be, when starting, the option to select a background display *command* http://grass.osgeo.org/grass64/manuals/html64_user/v.digit.html which could be set to d.rast map=name_of_raster also you can do it in the settings controls once in the tool, there's a tab for it. Hamish This mail was received via Mail-SeCure System. ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user This mail was received via Mail-SeCure System. -- Micha Silver http://www.surfaces.co.il/ Arava Development Co. +972-52-3665918 ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Re: Importing Dems with r.in.xyz
2010/6/7, Hamish hamis...@yahoo.com: Hanlie Pretorius wrote: I don't think it's this bug because this bug discards only one line of data. I don't get any data in because the number of coordinate pairs in the file is less than the number of cells in the defined region. Markus Metz: Weird. In 6.4, r.in.xyz does import a file where the number of coordinate pairs is far less than the number of cells in the defined region. (I just did a simple test with two input lines and a region with 26.5 million cells, got clean import and correct result) sorry, I'm not really grasping what the problem is. If you suspect there is something weird going on can you make the .xyz.bz2 file available for me to download, and supply the output of r.univar `wc -l` and `r.in.xyz --verbose`? Hamish Ok, the text file (6.1MB compressed) that I use as input to r.in.xyz is available at: http://www.nedbib.za.net/dems/ Output of r.in.xyz --verbose: - Reading data ... Writing to map ... r.in.xyz complete. 0 points found in region. - Output of r.univar: - total null and non-null cells: 1146474 total null cells: 1146474 Of the non-null cells: -- n: 0 minimum: -nan maximum: -nan range: -nan mean: -nan mean of absolute values: -nan standard deviation: -nan variance: -nan variation coefficient: -nan % sum: 0 - output of wc -l: 1146370 Output of r.info: - ++ | Layer:dem_2728ab_25m Date: Mon Jun 7 12:09:34 2010 | Mapset: PERMANENT Login of Creator: hanlie | Location: sa_tm_29deg_E | DataBase: /media/0847147784/grassdata | Title:Raw x,y,z data binned into a raster grid by cell mean ( dem_2728 | Timestamp: none | | | Type of Map: raster Number of Categories: 255 | Data Type:FCELL | Rows: 1011 | Columns: 1134 | Total Cells: 1146474 |Projection: Transverse Mercator |N: -49312.5S: -74587.5 Res:25 |E: -2987512.5W: -3015862.5 Res:25 | Range of data:min = -nan max = -nan | | Data Source: |/media/0847147784/data/CD-NGI/DEMS/25m dems/2728/ab/2728AB.ort.grass | | | Data Description: |generated by r.in.xyz | | Comments: |r.in.xyz input=/media/0847147784/data/CD-NGI/DEMS/25m dems/2728/ab/\ |2728AB.ort.grass output=dem_2728ab_25m method=mean type=FCELL\ | x=1 y=2 z=3 zscale=1.0 percent=100 - Thanks Hanlie ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Re: Importing Dems with r.in.xyz
g.region -p north: -49312.5 south: -74587.5 west: -3015862.5 east: -2987512.5 nsres: 25 ewres: 25 rows: 1011 cols: 1134 cells: 1146474 From the region settings you posted previously, I assume that the 1. column is north and the 2. is east, so: r.in.xyz input=2728AB.ort.grass output=2728AB.ort fs=, x=2 y=1 r.in.xyz complete. 1146370 points found in region. r.univar map=2728AB.ort total null and non-null cells: 1146474 total null cells: 104 Of the non-null cells: -- n: 1146370 minimum: 1473.52 maximum: 1618.85 range: 145.33 mean: 1519.76 mean of absolute values: 1519.76 standard deviation: 26.6106 variance: 708.125 variation coefficient: 1.75098 % sum: 1742202717.5849609375 Everything looks ok. Markus M On Mon, Jun 7, 2010 at 12:33 PM, Hanlie Pretorius hanlie.pretor...@gmail.com wrote: 2010/6/7, Hamish hamis...@yahoo.com: Hanlie Pretorius wrote: I don't think it's this bug because this bug discards only one line of data. I don't get any data in because the number of coordinate pairs in the file is less than the number of cells in the defined region. Markus Metz: Weird. In 6.4, r.in.xyz does import a file where the number of coordinate pairs is far less than the number of cells in the defined region. (I just did a simple test with two input lines and a region with 26.5 million cells, got clean import and correct result) sorry, I'm not really grasping what the problem is. If you suspect there is something weird going on can you make the .xyz.bz2 file available for me to download, and supply the output of r.univar `wc -l` and `r.in.xyz --verbose`? Hamish Ok, the text file (6.1MB compressed) that I use as input to r.in.xyz is available at: http://www.nedbib.za.net/dems/ Output of r.in.xyz --verbose: - Reading data ... Writing to map ... r.in.xyz complete. 0 points found in region. - Output of r.univar: - total null and non-null cells: 1146474 total null cells: 1146474 Of the non-null cells: -- n: 0 minimum: -nan maximum: -nan range: -nan mean: -nan mean of absolute values: -nan standard deviation: -nan variance: -nan variation coefficient: -nan % sum: 0 - output of wc -l: 1146370 Output of r.info: - ++ | Layer: dem_2728ab_25m Date: Mon Jun 7 12:09:34 2010 | Mapset: PERMANENT Login of Creator: hanlie | Location: sa_tm_29deg_E | DataBase: /media/0847147784/grassdata | Title: Raw x,y,z data binned into a raster grid by cell mean ( dem_2728 | Timestamp: none | | | Type of Map: raster Number of Categories: 255 | Data Type: FCELL | Rows: 1011 | Columns: 1134 | Total Cells: 1146474 | Projection: Transverse Mercator | N: -49312.5 S: -74587.5 Res: 25 | E: -2987512.5 W: -3015862.5 Res: 25 | Range of data: min = -nan max = -nan | | Data Source: | /media/0847147784/data/CD-NGI/DEMS/25m dems/2728/ab/2728AB.ort.grass | | | Data Description: | generated by r.in.xyz | | Comments: | r.in.xyz input=/media/0847147784/data/CD-NGI/DEMS/25m dems/2728/ab/\ | 2728AB.ort.grass output=dem_2728ab_25m method=mean type=FCELL\ | x=1 y=2 z=3 zscale=1.0 percent=100 - Thanks Hanlie ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] Re: Importing Dems with r.in.xyz
2010/6/7, Markus Metz markus.metz.gisw...@googlemail.com: g.region -p north: -49312.5 south: -74587.5 west: -3015862.5 east: -2987512.5 nsres: 25 ewres: 25 rows: 1011 cols: 1134 cells: 1146474 From the region settings you posted previously, I assume that the 1. column is north and the 2. is east, so: r.in.xyz input=2728AB.ort.grass output=2728AB.ort fs=, x=2 y=1 r.in.xyz complete. 1146370 points found in region. r.univar map=2728AB.ort total null and non-null cells: 1146474 total null cells: 104 Of the non-null cells: -- n: 1146370 minimum: 1473.52 maximum: 1618.85 range: 145.33 mean: 1519.76 mean of absolute values: 1519.76 standard deviation: 26.6106 variance: 708.125 variation coefficient: 1.75098 % sum: 1742202717.5849609375 Everything looks ok. Markus M Ahh, you have found the error. In fact, the columns should not be swopped, the region specifications should. I've retried the import and it works now despite the missing data and the DEM sits in the right place compared to the rest of my data. Thanks for everyone's help and my apologies for the confusion. Our national projection swops X and Y and reverses the direction of the positive coordinates, so it can get very confusing. Hanlie ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] Temporal Analysis
Greetings I have to do some simple-statistical TEMPORAL analysis between a long data-series. I mean, I have do some temporal average for each pixel, minimum and max. Instead of doing this statistical- analysis for all pixels in an image, I have to do this analysis for each image-pixel along its temporal series. Is there any function to do this? Or as anyone tried ? Thanks Nikos ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Temporal Analysis
Hello Nikos, just give r.series a try. regards, Martin On Montag, 7. Juni 2010 14:06:17 Nikos Dumakis wrote: Greetings I have to do some simple-statistical TEMPORAL analysis between a long data-series. I mean, I have do some temporal average for each pixel, minimum and max. Instead of doing this statistical- analysis for all pixels in an image, I have to do this analysis for each image-pixel along its temporal series. Is there any function to do this? Or as anyone tried ? Thanks Nikos -- Dr. Martin Wegmann University of Wuerzburg Institute of Geography Department of Remote Sensing Remote Sensing and Ecosystem Research Am Hubland 97074 Wuerzburg, Germany @ German Aerospace Center (DLR) German Remote Sensing Data Center (DFD) Phone: +49-(0)931-31-83446 Fax: +49-(0)931-31-84961 Email: martin.wegm...@uni-wuerzburg.de url: http://www.remote-sensing.uni-wuerzburg.de url: http://www.dlr.de/caf url: http://www.global-change-ecology.de ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] r.in.gdal- renaming bands
katrin wrote: I have a stack of images and when I import it to GRASS it starts to renaming as blue, green, red and then numbers. Why does it attribute those names since I'm not asking for it? r.in.gdal -k flag: -k Keep band numbers instead of using band color names (so the red,green, blue naming is incorrect, or you just don't want them?) r,g,b sets are grouped with the i.group command, displayed with d.rgb, combined into a single map with r.composite (loss of fidelity if you do that though) Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] r.in.gdal- renaming bands
Ok -k parameter In this case is incorrect giving the fact that the first band is not red :D) 2010/6/7 Hamish hamis...@yahoo.com katrin wrote: I have a stack of images and when I import it to GRASS it starts to renaming as blue, green, red and then numbers. Why does it attribute those names since I'm not asking for it? r.in.gdal -k flag: -k Keep band numbers instead of using band color names (so the red,green, blue naming is incorrect, or you just don't want them?) r,g,b sets are grouped with the i.group command, displayed with d.rgb, combined into a single map with r.composite (loss of fidelity if you do that though) Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] is r.average a weighted average?
Hi List, I have a question about r.average. If I get the average elevation of a DEM by r.average, is it a weighted average or have cells with the same value been counted only once? Thank you in advance. -- Eng. Margherita Di Leo Ph.D. Candidate Methods and Technologies for Environmental Monitoring Department of Environmental Engineering and Physics (DIFA) University of Basilicata Campus Macchia Romana 85100 - Potenza Italy Office: +39-0971205363 Web page: http://www.geofemengineering.it/GeofemEngineering/MargheritaDiLeo.html ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] r.in.gdal- renaming bands
Hamish pisze: katrin wrote: I have a stack of images and when I import it to GRASS it starts to renaming as blue, green, red and then numbers. Why does it attribute those names since I'm not asking for it? r.in.gdal -k flag: -k Keep band numbers instead of using band color names (so the red,green, blue naming is incorrect, or you just don't want them?) r,g,b sets are grouped with the i.group command, displayed with d.rgb, combined into a single map with r.composite (loss of fidelity if you do that though) Not always multiband images are composite rgb. For example SAGA GIS exports set of maps as a composite Geotiff, for which red, green, blue names would be a nonsense... 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] Temporal Analysis
Thank you Martin. I realized that one of the functions that I need, (counter of values bellow a certain threshold) is not available in r.series. Do you know, or do you have any suggestion, how to perform this? Thanks Best regards Nikos On Mon, Jun 7, 2010 at 1:12 PM, Martin Wegmann martin.wegm...@uni-wuerzburg.de wrote: Hello Nikos, just give r.series a try. regards, Martin On Montag, 7. Juni 2010 14:06:17 Nikos Dumakis wrote: Greetings I have to do some simple-statistical TEMPORAL analysis between a long data-series. I mean, I have do some temporal average for each pixel, minimum and max. Instead of doing this statistical- analysis for all pixels in an image, I have to do this analysis for each image-pixel along its temporal series. Is there any function to do this? Or as anyone tried ? Thanks Nikos -- Dr. Martin Wegmann University of Wuerzburg Institute of Geography Department of Remote Sensing Remote Sensing and Ecosystem Research Am Hubland 97074 Wuerzburg, Germany @ German Aerospace Center (DLR) German Remote Sensing Data Center (DFD) Phone: +49-(0)931-31-83446 Fax: +49-(0)931-31-84961 Email: martin.wegm...@uni-wuerzburg.de url: http://www.remote-sensing.uni-wuerzburg.de url: http://www.dlr.de/caf url: http://www.global-change-ecology.de ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Temporal Analysis
On Monday 07 June 2010, Nikos Dumakis wrote: Thank you Martin. I realized that one of the functions that I need, (counter of values bellow a certain threshold) is not available in r.series. Do you know, or do you have any suggestion, how to perform this? Thanks Best regards Nikos Hi Nikos, I can't seem to find it right now, but there was a discussion a while back regarding user-defined functions for r.series. I don't think anything came out of it, but one of the Martins or Markus' (I think) was able to put some nice working into a more consolidated stats library. Others may recall more details. The basic premise: implement a mechanism by which a vector (i.e. the array of values defined by a single cell but sliced through a time series of rasters) could be passed to an R function, python function, etc. that would do its work and return a scalar to GRASS. This seems like it would be hard to implement, but would add tremendous flexibility to time series analysis. Another approach might be to use the 'raster' package for R. Cheers, Dylan On Mon, Jun 7, 2010 at 1:12 PM, Martin Wegmann martin.wegm...@uni-wuerzburg.de wrote: Hello Nikos, just give r.series a try. regards, Martin On Montag, 7. Juni 2010 14:06:17 Nikos Dumakis wrote: Greetings I have to do some simple-statistical TEMPORAL analysis between a long data-series. I mean, I have do some temporal average for each pixel, minimum and max. Instead of doing this statistical- analysis for all pixels in an image, I have to do this analysis for each image-pixel along its temporal series. Is there any function to do this? Or as anyone tried ? Thanks Nikos -- Dr. Martin Wegmann University of Wuerzburg Institute of Geography Department of Remote Sensing Remote Sensing and Ecosystem Research Am Hubland 97074 Wuerzburg, Germany @ German Aerospace Center (DLR) German Remote Sensing Data Center (DFD) Phone: +49-(0)931-31-83446 Fax: +49-(0)931-31-84961 Email: martin.wegm...@uni-wuerzburg.de url: http://www.remote-sensing.uni-wuerzburg.de url: http://www.dlr.de/caf url: http://www.global-change-ecology.de -- Dylan Beaudette Soil Resource Laboratory http://casoilresource.lawr.ucdavis.edu/ University of California at Davis 530.754.7341 ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Temporal Analysis
hello Nikos, I would combine r.mapcalc and r.series. With r.mapcalc you could extract values below a certain threshold and do the r.series analysis based on this new dataset. e.g. for i in `g.mlist pattern='pattern_of_your_raster*'` ; do r.mapcalc $i_new = if($i threshold, $i, null()) ; done r.series input=`g.mlist pattern='*_new' sep=,` output=results method=sum regards, Martin On Montag, 7. Juni 2010 18:38:38 Nikos Dumakis wrote: Thank you Martin. I realized that one of the functions that I need, (counter of values bellow a certain threshold) is not available in r.series. Do you know, or do you have any suggestion, how to perform this? Thanks Best regards Nikos On Mon, Jun 7, 2010 at 1:12 PM, Martin Wegmann martin.wegm...@uni-wuerzburg.de wrote: Hello Nikos, just give r.series a try. regards, Martin On Montag, 7. Juni 2010 14:06:17 Nikos Dumakis wrote: Greetings I have to do some simple-statistical TEMPORAL analysis between a long data-series. I mean, I have do some temporal average for each pixel, minimum and max. Instead of doing this statistical- analysis for all pixels in an image, I have to do this analysis for each image-pixel along its temporal series. Is there any function to do this? Or as anyone tried ? Thanks Nikos -- Dr. Martin Wegmann University of Wuerzburg Institute of Geography Department of Remote Sensing Remote Sensing and Ecosystem Research Am Hubland 97074 Wuerzburg, Germany @ German Aerospace Center (DLR) German Remote Sensing Data Center (DFD) Phone: +49-(0)931-31-83446 Fax: +49-(0)931-31-84961 Email: martin.wegm...@uni-wuerzburg.de url: http://www.remote-sensing.uni-wuerzburg.de url: http://www.dlr.de/caf url: http://www.global-change-ecology.de -- Dr. Martin Wegmann University of Wuerzburg Institute of Geography Department of Remote Sensing Remote Sensing and Ecosystem Research Am Hubland 97074 Wuerzburg, Germany @ German Aerospace Center (DLR) German Remote Sensing Data Center (DFD) Phone: +49-(0)931-31-83446 Fax: +49-(0)931-31-84961 Email: martin.wegm...@uni-wuerzburg.de url: http://www.remote-sensing.uni-wuerzburg.de url: http://www.dlr.de/caf url: http://www.global-change-ecology.de ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Temporal Analysis
On Mon, Jun 7, 2010 at 6:38 PM, Nikos Dumakis nikosdu1...@gmail.com wrote: Thank you Martin. I realized that one of the functions that I need, (counter of values bellow a certain threshold) is not available in r.series. I have implemented it some time ago for this article http://www.mdpi.com/2072-4292/2/1/333 Estimating Daily Land Surface Temperatures in Mountainous Environments by Reconstructed MODIS LST Data I have implemented it for growing degree days (GDD) thresholding for insect development. Find it in GRASS 6.5 and 7 (also 6.4.1 once 6.4.0 is out): http://grass.osgeo.org/grass70/manuals/html70_user/r.series.html Hope this helps, Markus ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
