QGIS is a user-friendly, cross-platform GIS application licensed under the GNU General Public License.

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2
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0answers
219 views

How to render a transparent raster layer on top of one or more vector layers with PyQgis?

I been trying to render a map with a 3 vector layers and one raster layer. The idea is that the raster layer should be on top of the other 3 vector layers. The problem is that even when I add the ...
0
votes
1answer
81 views

Why are some features missing from Raster menu in QGIS for linux?

I am running QGIS 1.8 in Ubuntu/Linux (13.04), with GDAL 1.10 installed. There seem to be features missing from GDAL tools that are present in Windows version. For example, I can't find Rasterize or ...
3
votes
1answer
332 views

Changing the CRS of a shapefile

Im trying to convert shapefile from one CRS to another in QGIS. On the layer menu, I right click on the shapefile, save it as with other name and there I change the CRS to the desired one (WGS 84). ...
1
vote
1answer
47 views

Why are color settings not saved when exporting to a new file?

I extracted with QGIS a municipality from a state map, then divided it with a grid. I don't want the borders of the grid features to be seen so I changed the color of the map and the color of the ...
1
vote
4answers
349 views

Which UTM system do you recommend for Tamaulipas, Mexico?

I'm working with QGIS 1.8.0. Could anyone tell me which UTM system would be better to project a map of Mexico? There are too many to choose from. I have to convert my maps from WGS84 to UTM to do some ...
5
votes
2answers
848 views

How to calculate the number of cells with a given value?

I have a raster file where all cells have values between -3 and 7, no data value is -9999. Have can I calculate the number of cells with a specific value e.g. 6? Can I use the calculator?
4
votes
1answer
229 views

How can I accurately measure area of polygons using field calculator in qgis?

I have several polygon shapefiles, both set to WGS84 CRS. I have been using the google basemap with the Openlayers plugin, using the mercator CRS. On the fly CRS transformation is enabled. Should ...
1
vote
1answer
168 views

QGIS Extend Toolbar (GUI) Button Functionality via Python Plugin?

Is it possible to piggyback onto the QGIS split method via a python plugin? Are toolbar buttons accessible via the python API? This looks like the class that I need to access. Access ideas? ...
0
votes
1answer
184 views

Importing dxf as a vector layer or using dxf2shp function (Differences?)

I was trying to import a DXF file in QGIS. First tried using dxf2shp function but it didn´t work. I browse the dxf file and i put a name to the output and nothing was created in directory i chose. I ...
2
votes
1answer
521 views

Exporting geographic coordinates in QGis as projected (flat) coordinates

I've created some polygons with Google Earth which I'd like to convert to my flat map's coordinate system. I've loaded a few shapefiles into QGis of a county's roads, parcels, etc. The coordinate ...
1
vote
1answer
157 views

Why is there an offset between reprojection results of ArcGIS and QGIS from PSAD56 to WGS84?

I did a comparison of file system PSAD 56 to WGS 84 with arcgis and qgis and the difference is 8 m, why is the difference? This is a points file (shape) and it is in UTM Zone 19S.
7
votes
1answer
436 views

Creating contours with meaningful values from point data

I recently obtained a CSV containing the locations of all recorded bicycle accidents in Boston over the past few years. As an avid cyclist, I'd like to create a simple contour map that draws attention ...
1
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1answer
3k views

Import PDF to qgis

i have a PDF containing a region of Baltimore city that contains lots of polygons in it. you can download it from here: ...
1
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1answer
52 views

“merge” a raster data set on precipitation with a shapefile of administrative districts.

I'm currently using QGIS 1.8.0 I would like to "merge" a raster data set on precipitation with a shapefile of administrative districts. Basically my the aim is to figure out the precipitation in ...
0
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0answers
155 views

how can quantum be installed without administrative rights?

I have the impression from searching that this may have been possible with earlier versions but I don't know if it is possible with version 1.8. Thanks
0
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0answers
80 views

Mapping point data according to it respective value

The project I am trying to do is to map sum water quality (based on trace metals) data into QGIS. Each of the trace metals have their respective values and need to represent their concentration ...
1
vote
4answers
98 views

Add only unique features from another shapefile

I've got a problem that I am sure at least one of you have dealt with. I'm new to a company that makes use of a rather large database of point data. For whatever reason, the woman who was here before ...
4
votes
1answer
57 views

Dividing map into features with invisible divisor lines using QGIS?

I'm working with QGIS 1.8.0. Is there a way to divide a map with a grid but make the divisor lines invisible? I have a shapefile as the one in the left and I want it to see as the one in the right but ...
1
vote
1answer
72 views

Conversion of coordinates of “Bochum coordinate system”

I need to convert historic coordinate data into more recent Gauß-Krueger data. Specifically, I need to convert "Bochum coordinates" used till 1960 in the local coal mines into DHDN/Gauß-Krüger zone 2 ...
3
votes
0answers
315 views

QGis Save Raster as Rendered Image

In QGIS 1.9.0 Master, when you right click on a raster in the Layers Panel and select "Save As", you can select the output mode to be "Raw Data" or "Renedered Image". When selecting the Rendered ...
5
votes
3answers
574 views

is there any way to run a GIS (Esri, Qgis or mapinfo) on a Windows8 RT tablet?

I am looking for a good idea to run a GIS program on a Dell XPS 10 with the Wind.8 RT.Thanks for any
1
vote
1answer
76 views

Counting and sum by two layers

I´ve got to layers, both polygons. Layer 1 consists of propertiers, where ID is individually names. Layer 2 consists of lakes. The query I want is: Total count of squaremeters of lakes for each ...
1
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0answers
118 views

How to convert a symbol style set for ArcGIS for use in QGIS?

Is there a way to convert a symbol style set for ArcGIS for use in QGIS? There are symbols used in Incident Command I would like to use in QGIS, but can only find a style set for use in ArcGIS. The ...
1
vote
0answers
45 views

Can I use the PyQgis QgisPluginLayer to create heatmaps?

I am working in an application to generate maps from a bunch of MIF/MID files, I already created almost all the maps that I need, but, now I want to create heatmaps. I can't find any way of creating ...
0
votes
3answers
412 views

Calculating MCP in QGIS

QGIS 1.8.0. Scipy installed. Statsmodels installed. Using Sextante to try to calculate MCP. When I run the MCP calculation from the Toolbox, a layer is added to the file, but the layer doesn't ...
0
votes
1answer
55 views

Using LANDFIRE data in QGIS

I am wanting to use the LANDFIRE rasters in QGIS, but I cannot get all the files to load. I load the w001001.adf file in the directory that contains the data, but I cannot access the attribute table, ...
2
votes
1answer
244 views

Adding UTM Zone Number to Coordinates

The computer program that I'm working with requires an 8 digit UTM Easting for the coordinates of shapefiles (i.e., the UTM zone number must be included with each coordinate within a shapefile). The ...
2
votes
2answers
332 views

Vehicle tracking by QGIS

I need to do routing for a vehicle. A map with detailed turn-by-turn driving directions should be generated. For example, it should be like car race game in which the map with vehicle tracking is ...
2
votes
0answers
140 views

Spatial Precision for Editing in Multiple GIS Clients

I have something I'd like to discuss, I'll try to explain it first, why it's important, and I'll explain how ArcGIS handles the issue, which I think is a good way to handle it. Finally I'd like to ...
1
vote
1answer
185 views

Bring trails onto a Garmin nuvi GPS

I seem to be having a lot of trouble uploading Utah Trails onto my nuvi 50 GPS. Is it not possible? The Black hills national forest has a img file that is able to be loaded onto the GPS, but the ...
3
votes
1answer
360 views

Invert Color Ramp in QGIS

This is a real basic question, but I can't seem to find it. How do I invert the color ramp in QGIS? I am using RdYlGn, but I would rather use GnYlRd. Seems really easy, but I can't seem to find ...
0
votes
1answer
199 views

Polygon grid shape file for landmass

I am interested in generating a polygon grid shape file for the landmass of the world. What I have presently is two tables in postgreSQL. Table 1: Coastal area shapefile ...
1
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0answers
53 views

How do I make vectorlayer with sql on PostGis via python code

I need to make a vectorLayer and fill with the SQL's results on PostGIS via python code. I'm working with python 2.7, QGIS 1.8 and PyQt 4.5 How do I it ? thanks
0
votes
0answers
37 views

QGIS adding points using decimal degrees [duplicate]

As duck blind permits are sold, we need to add the location using lat/long. we are working in ArcView now but would like to move to QGIS- Everything I was able to find seemed to deal with importing ...
4
votes
5answers
1k views

Display ESRI Shapefiles in a map in a browser. (Not in google maps)

I have a series of shapefiles that I need to render as a map on a webpage. I have an ASP.Net server, although I would prefer something that will work on Linux servers. I would like to find an easy to ...
3
votes
1answer
160 views

Can one expose variables to the Python console from a plugin in QGIS?

I have a QGIS plugin that performs a long-running operation, eventually producing and loading new shapefiles into QGIS. (I have this as a plugin rather than just a function that can be called from the ...
5
votes
0answers
478 views

How to create a customizabe table in QGIS Print Composer?

I would like to add a custom table to a map layout created in QGIS. I would like a fair bit of control over the look of the table (borders, background colours of the cells, etc.), and it appears that ...
0
votes
1answer
76 views

How to know the real size of grid? [duplicate]

Im working with QGIS. When dividing a map with a grid I set in the paramters X=0.1 and Y=0.1. Could someone please explain what does that mean? I mean would the map be divided into 100mx100m squares? ...
1
vote
2answers
206 views

QGIS:what does it do “snap gcp coordinates to background layers” in the Georeferencer plugin?

Maybe is too obvious, but I don't find any precise documentation about this checkbox in the georeferencer plugin.
1
vote
1answer
66 views

problem in merging adjacent address polygons in qgis

I am having 15 polygon shape files of a sub locality of a city that is having address in their attribute table. I want to merge these polygons based on the address in the attribute table?how can i do ...
0
votes
1answer
171 views

How to count number of stores per company per region?

I have two layers. One point layer and a Polygon layer. It is simple to count the points in the polygon layer by the "points in polygon" function. But I also need some more information of the point ...
0
votes
2answers
159 views

How to count record points within a given area (electoral district)? [duplicate]

New user to GIS and to QGis but experienced data user. I have shapefiles for a state legislative districts. I have a set of individual voter records that I have geocoded. What I'd like to do is ...
0
votes
1answer
74 views

Value Map Attributes to Multiple Files in QGIS

I am hoping someone can share a way that I can some what automatically (none manual) associate a pre-defined CSV file for use with multiple shapefiles as an attribute Value Map. I have a number (in ...
0
votes
0answers
87 views

QGIS merge rasters error

I've been trying to merge some raster tiles at work and I've been getting an error message saying I don't have the correct permissions. This works fine on my home pc. Any obvious reasons for this? ...
0
votes
0answers
51 views

Borderlines of states subdividing my GRID

![enter image description here][2]I just merged a map of a country with its states, so I went from having 1 feature (the whole country) to 32 features. Is there any way to have the borders of the ...
0
votes
1answer
30 views

What is the meaning of “MULTIPOLYGON EMPTY” Message?

I am trying to run ST_Intersection function. SELECT ST_AsText(ST_Intersection(ST_Point(42.729123082000058,-96.619302355999992), ST_Point(42.72899715300008,-96.619410439999967))) FROM clu_08aug; I am ...
1
vote
1answer
374 views

QGIS Zonal Statistics just gives 'NULL'

Seems like such a simple plugin, but it just won't work. I'm trying to run Zonal Statistics to find the mean value of a raster's pixels within the area of a vector polygon, but all it will give me is ...
1
vote
1answer
118 views

Dividing map into features (whole squares)

I'm using QGIS 1.8.0. I divided a map of a state with its municipalities into many features using a GRID (small squares), but instead of creating one ID per feature (one ID per square), it creates one ...
1
vote
1answer
1k views

QGIS on Windows Surface

I was wondering if anyone has had any success running QGIS on the Windows Surface tablet? Specifically with the Windows RT OS. Thanks...
2
votes
2answers
201 views

Convert ASCII Grid Colorized to Raster

I have an ASCII Grid file + .prj file and can visualize this in qGIS. I can colorize it by going to properties and using a Pseudocolor Ramp. However, I want to export this now as a TIFF / Raster. ...