GRASS GIS (Geographic Resources Analysis Support System) is a free, open source geographical information system (GIS) capable of handling raster, topological vector, image processing, and graphic data.
2
votes
0answers
52 views
How to join nodes to network lines ( and not the other points)
I'm trying to do a shortest path analysis on my network. In order to prepare the network and attach polygon centroids to the roads, I used GRASS' V.NET operation=connect. the problem with this ...
2
votes
0answers
41 views
Temporal GRASS GIS framework
I am trying to follow the tutorial posted here. When I get to this part "Extraction of seasonal mean temperature" and run this code:
t.rast.extract \
input=temperature_mean_1950_2011_seasonal \
...
2
votes
0answers
114 views
Topology problems with QGIS/GRASS
*edited file links below
I'm working on several NGO projects at the moment, all of which are reliant on being able to use a district level map with some 490+ features, and I am running into some ...
2
votes
1answer
65 views
GRASS : r.resamp.rst error : “Not enough disk space--cannot write files”
Today, I am confronted to a difficulty I cannot manage.
When I try to use the tool "r.resamp.rst", it gives me as answer:
*r.resamp.rst input=map@PERMANENT ew_res=11 ns_res=11 pcurv=curv
...
2
votes
1answer
60 views
Issue while running grass from subprocess
I have a map based web application using geodjango. I needed to display the crime hotspots within a selected polygon area. I found that v.kernel is very good for generating heatmaps/hotspots. So in my ...
2
votes
0answers
87 views
Export to shapefile qgis
I am trying to develop hotspot map showing point density in our gis based web application. After searching for an option I have decided to use v.kernel command. I have a table containing some point ...
2
votes
1answer
84 views
Error when importing vector layer into GRASS
I am trying to import a vector layer into GRASS, but I keep receiving the same error. The values in the vector layer are important because I would like to use them to create a heatmap. What could I ...
2
votes
0answers
148 views
GRASS GIS - r.water.outlet - What is my mistake?
I'm new to GIS - more so in GRASS GIS. I installed GRASS GIS 6.4.3svn in my Windows 7 machine. No problem in installation.
Downloaded SRTM-Geotiff file
Location, Mapset all o.k
Used r.in.gdal to ...
2
votes
0answers
257 views
Simulate flood to assess Asset inundation footprints
I am trying to evaluate a number of flood gauges to assess at what levels of river height different flood risks would need to be issued. The gauges are currently set to warn of flood a couple of ...
2
votes
2answers
526 views
How to perform volume calculation in QGIS
EDIT 07/12/12
Ok, meanwhile I came to another problem I want to discuss.
I just tried around with the volume calculation with some layers and came to a point where I receive the following error.
...
2
votes
0answers
108 views
How to fix Graphserver warning “osmdb has no edges!”?
I'm really new to GIS.
I have some shapefiles data that I'm trying to import in graphserver. I'm doing:
gs_osmdb_compile output3.osm output3.osmdb
And the result is: WARNING: osmdb has no edges!.
...
2
votes
2answers
171 views
Hand fit curve and then apply to time series of rasters, make a map. How?
Maybe a data management problem, not too sure, but likely a challenge which someone has dealt with before.
I have a time series of rasters. I can summarise the information by taking averages of each ...
1
vote
2answers
85 views
How to join polygons and lines vector maps from openstreetmap?
I am struggling with the data format OSM gives me: I want to use OSM data for routing, but all round-abouts and parking lots are not in the lines layer. They are situated in the poly(lines) layer.
...
1
vote
2answers
322 views
GDAL-GRASS building fails
When I run ./configure --with-grass=/usr/local/grass-6.5.svn/ I get the following errors:
..........
checking for gdal-config... /usr/bin/gdal-config
using /usr/lib/gdalplugins as GDAL shared library ...
1
vote
2answers
1k views
How to set cell size for vector to raster conversion in QGIS GRASS plugin?
I'm converting a vector (loaded in GRASS plugin in QGIS (1.7.0.-wroclaw) and would like to convert this to a raster with a defined cell size. At the same time I need a value from the attribute tabel ...
1
vote
1answer
278 views
Shell script commands
I have this shell script:
#!/bin/sh
r.mapcalc water = 120
d.rast water
i=1
while [ $i != 100 ]
do
n=1
while [ $n != 10 ]
do
r.mapcalc < water.mapcalc
d.rast ...
1
vote
3answers
56 views
How do I active “Open GRASS tools”-button?
I have opened to GRASS layers and need to use the "Open GRASS tools"-button. This button remains unactivated somehow. Whilst the "Edit GRASS vector layer" right next to it works perfectly fine. What ...
1
vote
1answer
192 views
GRASS Geoprocessing in Python Script
I´m trying to get some GRASS geoprocessig tools running in a python script outside GRASS.
I´m able to import grass.script, but I´m not able to get the tools running yet. Does anybody know what I´m ...
1
vote
3answers
142 views
Looking for large GML files containing vector polygon data
I have few vector data files with 500 to 700 MB GML files. But I am looking for files larger than these preferably 1 GB, 2 GB. It would be helpful if somebody can provide some pointers regarding the ...
1
vote
2answers
266 views
What I'm doing wrong with the command r.out.ascii in GRASS GIS?
I have raster in .bil format which I want to save in GRASS GIS with r.out.ascii. I get this result in .txt file:
north: 1N
south: 0
east: 1E
west: 0
rows: 1
cols: 1
55537
I suppose it is something ...
1
vote
1answer
170 views
Why is the geonames not loading?
I want to import a geonames file. I downloaded the geonames .txt file from http://download.geonames.org/export/dump/
I used:
v.in.geonames input=PH.txt output=ph
but it displayed ...
1
vote
1answer
1k views
How to combine a vector and a raster file?
I want to combine a raster and a vector file. After combining, can I query on the resulting map to obtain a specific area? How?
1
vote
1answer
44 views
Grass7 - r.regression.multi and new raster
I am on the learning curve with Grass7. I managed to make r.regression.multi work, but there is one thing that would be of high interest for me: it is possible to create a new raster showing the ...
1
vote
1answer
135 views
Raster operation with grass.mapcalc
I need to iteratively add each raster map of viewshed analysis obtained from a series of single observer locations. For this i used grass.mapcalc with Python (GRASS 7 for Windows). However, my ...
1
vote
1answer
106 views
Grass r.mapcalc generates 1 cell map
I'm a GIS student and in my project I need to generate vegetation indexes. I've generated it succesfully yesterday using both python2.7 and grass gui .I'm using WinGRASS-6.5.svn-r54428-453 on Win7. ...
1
vote
2answers
240 views
count features in polygon shapefile A that fall within each feature of polygon shapefile B
I have two polygon shapefiles, each of which contain multiple (possibly overlapping) polygons.
Is there some way, using GRASS, to calculate the number of polygons belonging to shapefile A that fall ...
1
vote
1answer
131 views
hypsometric colors alà IMHOF, SYDOW or PEUCKNER
I need a hypsometric color-map to add it to my multishade-modell. (High Mountain between 800 and 4000m) There are a lot of differend typs explained in IMHOFS "Cartographic Relief Presentation". I want ...
1
vote
1answer
207 views
Command r.sunmask in GRASS
I have hypsometric model of relief, and I need to visualize shadows. I was suggested to use GRASS command r.sunmask, so I tried to set time values and run command, but it gives me an error
"ERROR: ...
1
vote
1answer
302 views
Grass GUI integration
Is it possible to embed the GRASS map display to a C# application? I know that a PNG image can suffice but to make the application more interactive it could perhaps be integrated. In essence I would ...
1
vote
1answer
367 views
How to create GRASS scripts in C# in Windows
Most of the tutorials that I have seen are under Python and Linux. Is it Possible to create GRASS scripts in C# or atleast in Windows. I can create scripts using a different language as a compromise ...
1
vote
1answer
700 views
How to select a raster file that is under a polygon in a vector file?
I am using:
v.db.select map=PHL_adm1 where=NAME_1='Bulacan'
My vector map is over the raster map. I want to select the part of the raster map under the polygon(NAME_1='Bulacan') of a vector. Is it ...
1
vote
1answer
121 views
OGR Python bindings
When I try to access one of the GRASS vector files through Python OGR bindings, it gives error:
Here is the script code in Python 2.7.3 IDLE (GUI) in Windows 7.
from osgeo import ogr
ds = ...
1
vote
1answer
86 views
Undefined reference errors installing GRASS addon
I am trying to install the r.geomorphons GRASS addon (available from http://sil.uc.edu/pdfFiles/jarek/r.geom.zip) in GRASS. I tried on Windows but gave up and decided the best thing to do was to try ...
1
vote
1answer
74 views
extract data from several images to different shapefile columns using GRASS
I am now working in grass and I want to extract raster values from several images to a shapefile. I have already created the columns in the .shp where the raster values will be stored but I am facing ...
1
vote
2answers
186 views
Network distance computations using GRASS
I'm an ArcGIS user who's interested in learning to use GRASS. Can anyone point out resources that will help me in learning how to obtain network distances between (1) residential locations (points) ...
1
vote
1answer
47 views
Watershed other than stream ( between two points)
Is there any method available to demarcate watershed for a location other than stream? I mean, if I want to find out the watershed for a place, where no stream available but, sheet of water can flow ...
1
vote
1answer
634 views
GRASS GIS: How do I run a batch (bash?) script?
I am in a GRASS database (in command shell), where I want to run a loop function. For example, I want to do an operation on many raster files that are in the database. I know this must be done through ...
1
vote
2answers
443 views
Interpolation of contours (from one “main-contour-shapefile”)
I calculated, that the best and smalest possible äquidistance (equidistant) for my map is 30m. After I generlized my DHM, I extracted contours of a intervall of 30m and smoothed them. Now I have my ...
1
vote
1answer
172 views
mdenoise/r.denoise: How to
I want to use mdenoise / r.denoise but i cant get it working. I have Xubuntu 12.04 and Grass 6.4.1
GRASS tells me after installing the plugin:
g.extension extension=r.denoise ...
1
vote
2answers
162 views
Can GRASS read Spatialite geometry fields?
I've looked at the question: How to import SpatiaLite data into GRASS? already. The links there talk about two separate tasks: Passing SQL to a Spatialite DB from GRASS and connecting to Spatialite ...
1
vote
1answer
75 views
mapping number of days a site is flooded from daily inundated areas maps
I have a set of daily inundated area polygons and would like combine them into one map that can give me a map showing the number of days a site remained inundated.
I am unable to figure out any ...
1
vote
1answer
154 views
Why can't r.patch find the rasters?
I have elevation rasters which loaded just fine in a GRASS session. They represent adjacent areas, so I want to meld them into one raster.
I ran r.patch using the GRASS GUI, and it would only accept ...
1
vote
1answer
174 views
How to keep (complex) color table when exporting from GRASS
I understand how to work with color tables within GRASS - but is there any way to preserve color tables when opening the raster in a different program?
For example, I created a color table in GRASS ...
1
vote
2answers
78 views
v.dissolve (and other scripts) not in GRASS path
I see that I have the v.dissolve module in my grass64/scripts dir, but it is not found in my path from the GRASS command line. I have the GRASS_ADDON_PATH environment variable set:
...
1
vote
1answer
80 views
How do I convert my coordinates to the limit of geographic region (outer edge)?
I am trying to use r.in.bin. The parameters of north, south, east, and west needs values:
north=float
Northern limit of geographic region (outer edge)
south=float
Southern limit of geographic region ...
1
vote
2answers
404 views
How to import .flt files into GRASS?
I am trying to import a raster file (.flt) into GRASS. The raster file (.flt) was generated from HEC-RAS. The said raster format cannot be imported into GRASS (it shows the error "file not ...
1
vote
1answer
319 views
Win7 GRASS 7 & i.landsat.toar
Hello has anyone got experience running i.landsat.toar ?
The output files I get are empty, the command takes but a moment to complete. However when run in verbose mode all the calculations are done, ...
1
vote
1answer
188 views
The resulting maps from a r.mapcalc script is not computed properly
This post is a continuation of my other post Why is my controlling shell script not working?. I created another post because this contains a separate issue that I encountered with the same scripts of ...
1
vote
1answer
61 views
QGIS contour lines shapefile to DEM help
I want to create a DEM from depth contours (shapefile) in QGIS. I've been trying to work out how to do this based on this previous question, notably from this link from that page, however I'm stuck, ...
1
vote
2answers
39 views
contour lines from point shape attribute
I have a point shape file and one of the attribute refers to the altitude.
Is is possible to obtain a contour lines shape file in GRASS?
