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

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1answer
152 views

Sum of point attributes inside hexagons using QgiS UI

I'm very new to Qgis so I would very much appreciate any help you can give me. I have a point shapefile that corresponds to locations of animals captured. I've joined a table to this shapefile with ...
2
votes
1answer
707 views

How to zoom to a selected feature with pyQGIS

I want to create a function that selects a feature and zooms to it (similar in QGIS). Therefore there is following function: QgsMapLayerRegistry.instance().addMapLayer(self.vlayer) def zoomTo(self): ...
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2answers
409 views

How to develop a Canopy Height Model of LIDAR data in QGIS?

I am having a DTM and DSM files .I want to develope a Canopy Height Model in Qgis is it possible?
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1answer
69 views

How can I know the number of polygons in a selected area in QGIS

How can I know the number of polygons in a selected area in QGIS? Can I use the Select features tool? How can I use? Thank you
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1answer
569 views

How to read attributes in pyQGIS and QGIS 1.8 without setSelectedFeature

I add a vector layer to a map with QgsMapLayerRegistry.instance().addMapLayer(self.vlayer) later the attributes are read with def select_all(layer): layer.select([]) ...
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1answer
864 views

Where are the 3d analyst tools available in QGIS?

I want to know whether we can perform 3d analyst in Q-Gis? If yes, means where is that option present?
5
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1answer
193 views

Which GIS Software is Right for small manufacturing trends analysis?

I'm a graphic designer who has been tasked with choosing a mapping platform for the manufacturing company I work for. One of my colleagues began our project by using a trial version of ArcGIS to ...
4
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2answers
980 views

What dissolve tool in QGIS allows me to summarize statistics for multiple attributes?

Is there a tool or plugin in QGIS that resembles ArcGIS 10's Dissolve tool? I'm trying to dissolve several polygons (parks) around the boundaries of another layer of polygons (cities), while ...
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2answers
237 views

Stop rounding values in Qgis attribute table

I am calculating the areas of my polygons in Qgis using $area and everything works fine until I click on "save". All my values are rounded to an integer. I tired setting the output field type to ...
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1answer
249 views

How to compute area for polygons in an EPSG:4326 shapefile?

I have a shapefile covering the whole globe, in EPSG:4326 (geodetic WGS84). I would need to compute the polygons areas in a metric such as km2. How can I do that in QGIS or with gdal/ogr and having a ...
4
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1answer
699 views

How to get SAGA working with QGIS Sextante?

I just created my account on this forum to find an answer to a stupid (?) problem I can't deal with. First, let's precise I just (some months ago) learned on my own what GIS was, and gave it a try ...
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0answers
213 views

Point in polygon analysis fails with “TypeError: arguments did not match any overloaded call”

I am using QGIS 1.8 on Windows 7 I want to perform a point in polygon analysis using the Vector > Analysis Tools menu. My point layer is the result of a SpatiaLite query which returns 10'000 points. ...
3
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1answer
821 views

How to add CSV data with no coordinates to a polygon layer in QGIS?

I would like to add attributes from an spss database (around 300 cases) to a polygon layer in QGIS. Both datasets have a column with unique IDs. I exported the spss data to a CSV file which does not ...
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0answers
59 views

QGis overlap labels

I have a csv file imported into QGis 1.8 and this layer is receiving real time data.Into this attribute table layer there is a field which values i use to label it but overlapping all values when ...
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2answers
92 views

How do I adjust transparency on heatmap so that I can see background raster map? QGIS 1.8.0

I have created a raster heatmap for the first time, but I cant seem to adjust the transparency settings to let me see another background OS raster map beneath it. I have attempted to swap the ...
2
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1answer
130 views

Creating pop-ups on point layers

i have a postgresql database which is refreshed all 10 minutes and i need to create graphs in pop-up with the data. When i click, a pop-up (or annotation ?) appears. How can i make it possible ? ...
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0answers
63 views

Coxcomb chart in qgis

I would like to use special pie chart for my map, where the angle is not important, but area or radius of the arc carries information. I found, that this type of pie chart is calling ...
0
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1answer
421 views

How to use a database in Qgis

What is the primary use of database in Q-Gis? How to connect to a database in Qgis?
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1answer
298 views

convert shapefiles to cad files

hi i'm having a difficulty in converting shapefiles to cad file. i'm currently using the ArcGIS 9.3.1 version and i tried to convert it using the toolbox>conversion tool>to cad>export to cad....the ...
3
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1answer
474 views

How to add complex Emergency Symbology (TrueType fonts) to QGIS?

In other packages I would simply ensure the TrueType font (+.ttf) was loaded on the operating system and it would be available for use. QGIS seems to rely on making your own. The symbols I wish to ...
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1answer
86 views

Can this compilation and display of species frequency data be improved? QGIS 1.8.0

As a newbie on QGIS, I would like to find out if the way I put a species frequency map together could be improved upon. I had to map the presence or absence of 7 plant species surveyed in 30 2m x 2m ...
6
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1answer
1k views

Identify polygon overlaps within single shapefile

Using either QGIS (1.9) or ArcInfo (9.3.1) I'm trying to identify unique overlaps of prehistoric building footprints from an archaeological site recorded within a single polygon shapefile. While the ...
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2answers
95 views

Why can't I save csv as a shapefile

I am trying to follow the instructions given here, Tutorial: Making Heatmaps using QGIS and GRASS , to build a heat map with my own data. I taken the first step and imported a csv data table into the ...
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4answers
161 views

How can I calculate different polygons by different attributes?

I'm doing my master thesis and want to calculate different polygons (in QGIS 1.8 for Mac) in four different columns which I defined by different attributes. i.e. some of the attributes in the first ...
0
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1answer
174 views

Compile Qgis source : Links errors (Windows)

I am actually trying to compile the source of the qgis git : https://github.com/qgis/Quantum-GIS In order to compile it, I follow the steps of the tutorial here : http://www.qgis.org/api/INSTALL.html ...
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0answers
91 views

How to spatial join points attributes to layer with two (or more) overlapping buffers in QGIS?

I'm working with QGIS 1.8 and I've got 3 layers : 2 points layers, and 1 layer composed of the buffers of one of the points layer. I'd like to retrieve the informations, for the point layer that ...
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0answers
79 views

Why is it that QGIS shows only one attribute table on all layers?

I have checked the "Select Single Feature" before clicking the Attribute Table but even if I choose a different layer, only one attribute table is shown.
3
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1answer
104 views

How do I make line symbols intersect cleanly without showing edges in QGIS?

I digitised a map showing electric grid lines. I merged a number of lines into a single feature. Now, I'd like these lines to be displayed so that the intersections appear continuous. At the moment, ...
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1answer
225 views

How to create “two-dimensional” color ramps in QGIS?

Is there a way in QGIS to create a "two-dimensional" color ramp for the graduated symbology; i.e. a color ramp that determines a color based on two different attributes? My situation is that I want to ...
0
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1answer
120 views

Cannot import Grass in Console of Qgis (1.9.0 Master)

I can't import Grass in Console of Qgis (1.9.0 Master). I am guessing it is because of some Grass environment variables which are not set up correctly. However I don't understand why it is working ...
3
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1answer
119 views

Is there a way to create a plugin in C++ without compiling all the Qgis source?

This is my second post and I apologize if it's post the same day on the first. After several researchs, I found the only way to create a plugin in C++ is to compile the Qgis source with the plugin ...
2
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1answer
3k views

make: pyuic4: command not found

I need to develop a QGIS plugin for a project. First, I launched the following command for the installation on Ubuntu 12.04: sudo apt-get update sudo apt-get install qgis sudo apt-get install ...
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2answers
1k views

projection change to create buffer in QGIS

I am about to become desperate... I like to create buffer around several points - if possible - with a declaration of the size in km of these buffers. Just to show you what I am working with: My ...
0
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1answer
46 views

Compile a plugin in 1.9 Qgis-dev

I am actually learning qgis and how to devellop a plugin. I have to write this plugin in C++ and not python because people coding in C++ want to modify it after. I have found some plugins in the git ...
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1answer
222 views

Career advice in Gis field [closed]

I am a B.Tech graduate(2013) in Geo Informatics and Geo Technology.Presently, i am working i an company as Junoir Executive in Gis . I also know some programming languages like "V.B.net" and C#.My ...
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0answers
30 views

how to divide a Area shapefile into multiple segment, so that each segment will be a seperate feature in attribute table? [duplicate]

I'm very new to GIS, I'm using QGIS and here's what I want to do: I have a shapefile of an area . I want to divide that area into multiple segment (not grid), so that each segment will be a ...
3
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1answer
196 views

What's the projection of this albanian military map?

I've received some very useful maps of Albania for my work (scale 1:25000) and I would like to georeference them in order to put them together to one Map for my destined regions. Unfortunately I ...
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2answers
183 views

Measurements across UTM zones, how to apply spatial parameters to a customize a projection?

I have a survey grid that spans 3 UTM zones. Using http://www.epsg-registry.org/ I can get an indication of what projections are available. Where can I find more info on the patterns of distortion ...
3
votes
1answer
87 views

Can I use predefined list of values from Postgis when I draw lines in QGIS?

Lets say that we have 2 tables in Postgis: Table 1 (PIPE): -ID -pipe_type_id -geometry Table 2 (PIPE_TYPE): -ID -type foreign key PIPE.pipe_type_id - PIPE_TYPE.ID Table PIPE is empty. Table ...
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1answer
321 views

Pie-Chart Coordinates in QGIS

I have a map of a region and I am plotting pie-charts (as diagrams) over every country in that region in QGIS (1.9.0). I also need to connect those pie-charts with lines (which I am creating in the ...
2
votes
1answer
94 views

Is there a way to add drop-down list of predefined variables to R-script menu in SEXTANTE QGIS?

I would like to create a drop-down list of variables (similar to what it is done for layers input) for my R script menu in SEXTANTE. Is it possible?
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1answer
415 views

Can QGIS read ESRI TIN file directly?

Can QGIS open directly a TIN file generated with ArcGIS?
4
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0answers
78 views

Is there a way to label a layer using its file name or layer name?

Is there a way to label a layer using its file name or layer name (if I'd change it in Layers window TOC)? I tried some functions but I'm not good on that. I have lots of shapes (lines) and it would ...
1
vote
1answer
286 views

OpenLayers Rendering Error [duplicate]

I'm using QGIS to render some air quality modelling results. I'm having issues with the OpenLayers Plugin whenever I have another vector layer active. The plugin works if it's the only layer in the ...
1
vote
1answer
118 views

Quantum GIS Standalone Browser

I don't think the QGIS standalone browser is working right on my computer. The only tab I can view is Param. The Metadata, preview and attributes tab are all grayed out. When I select a .shp for ...
0
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1answer
243 views

Convert / interpolate delimited text csv points grid to surface

I've got 12 delimited text csv files with regular pseudo-gridded points for temperature and salinity which look like this when zoomed in (inc distances) and this when zoomed out. I'm trying to convert ...
3
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1answer
106 views

How to extract coordinate pairs of crossing points of two polygons in PostGIS?

Extracting coordinate pairs of crossing points of two polygons in PostGIS Is it possible to extract x,y-coordinate pairs of crossing points of two overlapping polygons in PostGIS? Suppose there are ...
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2answers
133 views

Read raster value at mouse position

I have raster layer imported in QGIS. How can I read value of the variable represented by the raster at mouse position? I just have a new raster layer and I want to read values at random places to ...
2
votes
2answers
2k views

QGIS, Table Manager cannot rename column title

My current attribute table has a column whose title exceeds the ten letters maximum. I installed Table Manager, hoping I could rename the certain field to further use it (in order to add some ...
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2answers
462 views

How to search and move to feature in QGIS?

After solving how to search text string I need to move to the selected feature. Is it possible to do that?