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

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1answer
486 views

What are Bands, Dimensions, and Histograms in QGIS?

First; I can see a band as synonymous with a channel in an image editing program like GIMP, is this correct? If so then bands play the role of color mixing and masking. Are there any other ...
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0answers
30 views

Why does my QGIS want to create so many icons? [duplicate]

Not sure on protocol here--I asked this previously, but the responses petered out-- Every time I open a Print Composer, a box comes up, and text flashes by saying, "Creating icon for file [various ...
2
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1answer
209 views

Sum line length with clip intersect? [closed]

SELECT sum(st_length(st_intersection(POLY.geom, LINE.geom))) AS sum_line_length... Is this function OK to calculate the sum of lines length? Wonder if it do the clip line where one line go from one ...
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1answer
333 views

Cannot install TimeManager 0.7: no module named six

I was able to extract and copy dateutil to C:\OSGeo4W\apps\qgis\python\dateutil and the error saying that dateutil wasn't found disappeared. But now I am getting the error no module named six. Tried ...
2
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1answer
373 views

QGIS rounds up the coordinates to six decimals when saving layer changes

I have the problem that when I create a new point (in a point layer) or a new line (in a line layer of course) and I save the changes to the layer (so NOT the project save) then QGIS rounds up the ...
3
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1answer
77 views

What defines a Class in the Heat map plugin?

What defines a Class in the Heat map plugin? As in: "Black holes like that are usually caused by raster values exceeding the range of the color ramp. Try adding another class with a higher associated ...
2
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1answer
52 views

How to make a certain attribute Toggelable? [duplicate]

I have imported data from an excel spreadsheet containing lat,long coordinates associated with other attributes such as current operator of each point (well). I imported as a tab delimited file, then ...
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3answers
3k views

How to snap lines to points automatically?

I have two vector shapefiles: One file is points representing manholes and the other is a polyline file representing pipes leading to and from the manholes. I need to snap the lines within a ...
3
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1answer
1k views

How to convert jpg file to shapefile? [duplicate]

I am developing a GIS application like this: By now my steps are: I have got a jpg file, 5040 x 8179 dimension. In this map, the roads, rivers, towns etc. are marked. I am using .Net to develop ...
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1answer
368 views

Find closest point from origin in QGIS and display measure line in composer

I have a location point. there are several constraints areas surrounding the point. Is there a way to calculate the closest point of this constraint from my point and to display the distances as a ...
6
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2answers
788 views

How to implement multivariate hex bins?

I have two point datasets that I am analyzing and I wanted to implement a multivariate hexbin approach for displaying this data. I have managed to cobble together an approach using QGIS SVG symbols ...
3
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1answer
572 views

QGIS Print Composer Export problems

When I attempt to “Export as PDF” a Print Composer image, it hangs up until I press cntrl/alt/del, whereupon I learn that QGIS is not responding and needs to be closed. I’ve tried this as jpg, jpeg, ...
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1answer
87 views

gdal_contour creates an empty shapefile

I am running: gdal_contour -a elev hazard_interp4.asc haz_ak_contour_4_10 -i 10 the hazard_interp4.asc file has values in band 1 (singel band gray). With the above command, I get a shapefile that ...
4
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1answer
127 views

Automatically build branches of a river network?

A small non-profit, specializing in fish habitat restoration, has asked me to link a spreadsheet of field notes to their gis. What we have is: 1) A spreadsheet of field notes for small fish streams. ...
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0answers
170 views

Heat Map trouble: Is this a data formating problem?

I'm playing with the heat map plugin with QGIS. I've run through QGIS tutorial: http://docs.qgis.org/html/en/docs/user_manual/plugins/plugins_heatmap.html, using the airports data set as explained ...
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0answers
253 views

GeoTiff.lib: TiePoints only without ModelPixelScale do not get georeferenced in QGis

I have an image that has been georeferenced (geotiff.lib) by more than 3 tie points (x y 0 long lat 0 ...) and added following geotiff keys GTIFKeySet(gtif, GTModelTypeGeoKey, TYPE_SHORT, 1, ...
3
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0answers
145 views

How does Zonal statistics handle pixels that are on the border of the polygon?

I am using the plugin zonal statistics to calculate the sum of the raster cells within polygons. How does this plugin handle pixels that are on the border of the polygon, are those cell values ...
4
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2answers
127 views

One of my ID numbers for my polygon is not being shown when I label my layer. How do i fix it?

I have 20 polygons and when I tried to label the layer with the ID numbers only 19 appeared. For some reason my first polygons ID number is not being shown and I dont know why. Am I missing something ...
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0answers
414 views

How to upgrade from QGIS 1.4 to 1.8 on Linux Mint 12?

I've been trying to upgrade from the Enceladus 1.4 version of QGIS to 1.8 on a Thinkpad T42 running on Mint 12. When I try to upgrade from within QGIS help menu I receive the following error message: ...
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1answer
106 views

Problem loading raster to PostGIS using QGIS

I am having trouble loading a raster (.asc) file to PostGIS 2.0.1 using the plugin Database - PostGIS Raster - Load raster to postgis in QGIS 1.8.0 on Win Vista 64 bit. I get the following error ...
0
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1answer
163 views

gdalwarp cant find libproj.dlib

Thought I had finally got Python, gdal and QGIS to play nicely together but just tried to do a batch transform using a bash script to call gdalwarp and it claimed it couldn't read the libproj.dlib ...
2
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1answer
396 views

How to realign (PostGIS) layers in QGIS?

I'm trying to realign layers in QGIS. As you can see here, the "background" light-blue layer is not aligned with the top layers. I'm working with pgAdmin III and importing PostGIS Layers in QGIS. My ...
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3answers
2k views

Free Imagery WMS Feeds in QGIS

I was wondering if anyone knows of a free WMS of imagery that I could use within QGIS. The imagery does not have to be high resolution (Blue Marble even). I would like to have a base imagery feed ...
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0answers
65 views

When digitizing, objects are not saved well

I've some problems with digitizing. If I draw a line or a polygon, the line or polygon is saved in the attribute list, but not visible and its location is not saved either (when I zoom to the object ...
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4answers
406 views

How can I create polygons of the area surrounded by roads / lines?

I'm currently trying to create polygons that represent the areas surrounded by roads. The roads are stored in PostGIS as points / lines so I have flexibility over what I can do with them. I'm ...
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0answers
530 views

Distance Matrix in QGIS

Can anyone help me with the distance matrix tool in QGIS? Is there a tutorial about it? It sometimes crashes when I use it and the values that it produces seem strange. I am a beginner in QGIS, so I ...
5
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1answer
2k views

How to convert coordinates in a .csv into another CRS in QGIS

How can I convert coordinates which are stored in a csv and in a certain format in a different CRS, i. e. I want to convert GK 3 (EPSG:31467) into WGS 84 (EPSG:4326). I am using QGIS and already ...
2
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0answers
153 views

how to intersect a raster subset with a buffered vector layer (points) in QGIS?

I am a bit new in the GIS and qGIs sphere so maybe my question will look a bit naive, but at the same time it means it should probably be easy for most of you guys ;-) I work in QGIS.I have 2 layers: ...
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1answer
233 views

Qgis - Raster clip Problem

I tried to use the Raster (Extration) tool "clipper" and I always get this error log: What is my problem? Fehler bei der Ausführung von Python-Code: Traceback (most recent call last): File ...
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2answers
549 views

Is there a way to get correctly aligned print export with openlayers plugin?

I am a beginner using QGIS (1.8.0 Lisboa) on a Mac (OS X 10.6.8 Snow Leopard). I work on a file with two layers in the following sequence (top to bottom): a vector polygon layer with a few outlines ...
3
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1answer
1k views

How to convert shapefile to vector emf?

I want to convert a shapefile to an EMF file. The EMF file must be a vector image, not a raster image. Please suggest to me some good packages or tools. Thanks in advance.
3
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1answer
230 views

Why is my Polygon (WGS84) in SpatiaLite 4 not displayed by QGIS? [closed]

I made a polygon in a SpatiaLite 4 database as follows: INSERT INTO test_pg (id, name, geom) VALUES (3, 'test', ST_PolyFromText('POLYGON((8.556824 47.185269, 8.611009 47.185269, 8.611009 47.218568, ...
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1answer
71 views

Why does Print Composer take ages “Creating icon for file …”?

Every time I open a Print Composer, a box comes up, and text flashes by saying, "Creating icon for file [various random image files that I have on my computer]". It then pauses, and does it again, and ...
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1answer
215 views

Which horizontal unit is used on the table of the Profile Tool?

Does anyone knows what horizontal unit is used on the table of the "Profile Tool". Vertical is in meter but I don't know about the horizontal axis. Knowing the length of my profile, I tried to divide ...
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0answers
91 views

How can I snap 2 lines in QGIS so the st_distance between them is 0?

Sometimes when I snap the ends of 2 LineStrings together and I check the st_distance between those endpoints I get a value in the order of 1.1E-10 while at the same time when I check for equality of ...
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0answers
223 views

Does Polygonize in QGIS 1.8.0 work correctly?

Does anyone else have issues with the Polygonize function in QGIS 1.8.0. When i use it is to extract details from larger raster images, through raster calculator, then polygonizing the resultant ...
2
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1answer
1k views

QGIS Python version

I have brewed python 2.7.3 onto my Mac (Lion), and installed shapely via pip install shapely. The Polygonizer plugin, however, does not find the shapely library. I see when QGIS loads a Python ...
2
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3answers
2k views

Joining attributes of polygons and points by location in QGIS

I have two shapefiles.... points containing a number field 'response_time' a polygon grid of square polygons containing fields including 'PNTCNT' with the number of points per polygon, calculated ...
4
votes
1answer
207 views

How to include streaming media into an OpenGeo system to monitor live-tracked animals?

I am wondering how to include streaming media (video), or camera feeds, into an OpenGeo system to monitor live-tracked animals. I am currently doing so with different applications, but I want to do ...
0
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1answer
303 views

Does QGIS support vector Rubbersheeting? [duplicate]

The task is to rubbersheet two vector layers one with a projection like UTM WGS 84 Zone 45N
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0answers
48 views

Spatial adjustment for vector shp files in QGIS [duplicate]

How to do spatial adjustment for vector shp files in QGIS? I have a set of 4 cadastral maps of adjacent locations. I have converted them form DWG to DXF and then to vector shapefiles. They are not ...
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2answers
528 views

How to use a hillshade dataset in QGIS?

I received “Hillshade” data that I'm trying to use in QGIS. When I check the "Pseudocolor" option under "Color map", I get many colors, apparently corresponding to the terrain, though it doesn't ...
2
votes
1answer
156 views

How to symbolize points using line symbols of varying rotation and width?

I've been along a stretch of coast and recorded the orientation and thickness and locations of several igneous intrusions. I've managed to set up a project in QGIS with a point for each intrusion, ...
1
vote
3answers
602 views

Why does QGIS not detect the CSV/DBF column headers?

I am trying to import a csv or dbf into qGIS so I can perform a join on a shapefile. However, qGIS is not detecting the first row as header names. I know I've done similar joins before and there's ...
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1answer
135 views

How can I import ALOHA .pas plume file into QGIS?

I am trying to find a way to import ALOHA's plume model (.PAS) into QGIS? I have not been able to find anything showing how to accomplish this outside of using ESRI-based tools.
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1answer
212 views

Is it Possible to Convert a GRD File into an ASC File in QGIS?

Is it possible to convert in QGIS a GRD file (that was created in MapInfo) into an ASC file (that can be imported into SAGA)? Is it possible to "extract by mask" a section of a GRD file in an other ...
4
votes
1answer
275 views

How can I split a segment into two segments?

The problem is how to split segments or in other words how to insert new points into a polygon so that the segment where I created the new point is now two segments connected by said point. Every time ...
3
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1answer
177 views

Is there any way to have the legend text above the symbol and beside it, not just above?

Is there any way to have the legend text above the symbol and beside it, not just above? What i do at present is to cut the end of the text off and insert a label then group them, however i want to ...
4
votes
1answer
215 views

Where to report QGIS and QGIS-Plugin bugs?

I often find bugs in Qgis and its Plugins. I would like to ask about this on the internet but I do not seem to find the proper place to address this issue. Are there any instructions?
2
votes
2answers
105 views

Why does “save” overwrite the “capture point” function? [duplicate]

I am very new at using QGIS. I have the standard installation (no additional plug-ins). I have several polygons and each polygon is formed by a number of segments. What I am trying to do is to connect ...