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

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0answers
47 views

Shapefile wrong visualization [closed]

Just passed from 1.8 to 2.0.1. Opening a previous format project, some layers are visualized only at [each time] different scale; visualized at 1:313593 only if "zoomed at layer extension", otherwise ...
3
votes
2answers
234 views

How to export a vector layer to a new layer and take extent from canvas?

I want to create a new vector layer based on an existing one and the extent should be based on the current extent of the canvas. How do I do that? Edit: I am looking for a quick way to do that (a ...
0
votes
0answers
76 views

Merge (a lot of) features using QGIS or other open source

I have one shape-file with a lot of features (polygons) and if I try to merge these into one big polygon in QGIS it takes days to complete the merge. So I wonder if there is another way? I saw this ...
4
votes
4answers
293 views

How to convert result of dissolved buffer into individual polygons?

I am wondering if there is a way to easily split results of a disolved buffer into individual polygons? E.g in the screenshot below all of these buffers are one item, can I split them into individual ...
2
votes
1answer
164 views

QGIS 1.8 Vector layer from ODBC connection [duplicate]

I have successfully set up an ODBC link from a FileMaker DB to QGIS, and using Layer/Add Vector Layer I can get a layer with a fully populated attribute table listed in the Layers Panel. I now want ...
2
votes
3answers
104 views

Problem with deleting features/objects in Attribute Table

I am a new to the field of GIS-Software. So i hope for your patience. English is not my native language so sorry for that too ;). My overall goal is to export a DXF-File with just the special objects ...
1
vote
1answer
55 views

Error reading database file from: /Applications/QGIS.app/Contents/Resources/resources/srs.db

I've suddenly started getting the following error using QGIS 2.0.1 on Mac: Error reading database file from: /Applications/QGIS.app/Contents/MacOS/../Resources/resources/srs.db Because of this the ...
2
votes
1answer
1k views

QGIS 2.0 without MySQL connector

On a mac (Mountain Lion), after a major upgrade to GDAL (1.10) and related frameworks from KyngChaos page, QGIS 2.0 doesn't show any MySQL connector: Add Vector > Database > ... The driver ...
5
votes
1answer
235 views

QGIS - Changing Legend Size with Python

In QGIS, I use the python console to generate image files through the composer. In particular, I am creating a map with a legend. The legend is too big. It occupies about 1/8 of the image. I would ...
2
votes
2answers
64 views

Points near corner

I have a road network (lines) and some POIs (points). These POIs have the information of street name on their attribute table. I've found that some street name from the POI doesn't match with my road ...
1
vote
1answer
133 views

How to convert format and CRS of many shapefiles to kml (or csv, json..)?

I tried to use QGIS to transform shp files in kml and to translate the CRS to use in a google maps application. My problem is that I have a lot of shp files that i can open in a bulk manner by drag ...
2
votes
1answer
67 views

How to format raster legend in QGIS?

Using QGIS 2.0, I have created a color legend for raster values in the print composer. By default each color swatch appears to the left of its label in the legend but I want the color swatchs to ...
2
votes
0answers
75 views

QGIS crashes when trying to open ecw files

I added Ubuntugis unstable repo and installed Qgis, libgdal-ecw-src, libecwj2-3.3 but still does not work. When I attempt to open an ecw file with Qgis it crashes and tells me: 'std::length_error': ...
4
votes
1answer
788 views

Is there a way in qgis 2.0 to prevent overlapping labels?

Is there a way in qgis 2.0 to prevent overlapping labels? I have a layer with a large geographical extent, which means a hell of a lot of labels. Many of them collide and it looks really bad. Is ...
2
votes
0answers
284 views

QGIS 2.0: Automating tasks, text files and shapefiles

Wondering if it's possible to automate some repetitive tasks in QGIS (2.0). This is my general workflow for importing some xyz type text files from another software package which export (not overly ...
1
vote
0answers
246 views

Unable to use pyQGiS in a custom application - import arcgis.core error

I'm using windows 7 and/or 8 64 bit with QGiS 2.01. I'm wanting to us the pyQGiS tools in a custom python application outside of the QGiS environment (i.e by running a python executable located in ...
3
votes
2answers
113 views

Why are font and line sizes different in QGIS's Print Composer and how do I normalize them?

Why does my map look so different when I look at it in the QGIS print composer? The widths of lines change, the size of markers change, the size of fonts change. Is there any way to have the two ...
2
votes
0answers
262 views

How to resize a polygon (rectangle or circle) in Qgis?

Yes I used the Rectangles Ovals plugin to create a rectangle then rotate it and move it nto position. But if you want to resize it that is where the fun starts because it is just a polygon with four ...
2
votes
1answer
437 views

How to create a QGIS action which copies features between layers?

i tried (i never tried before...) to write a simple python code like action in QGIS on my "XXX" vector layer that: open a layer "YYY" copy the selected feature on my "XXX"layer paste the selected ...
1
vote
0answers
31 views

How to make gdalbuildvrt available in processing modeller?

I would like to make a model in QGIS that builds a virtualraster from several raster files. Unfortunately the gdal function is not available on the modeller. So, my question is: how to make this ...
1
vote
3answers
485 views

How to create random point in according polygon for each dataset entry in a list (with R)

I have an area divided into polygons, and a dataset of observations which has a common field with the polygon layer. I now would like to generate a random point for each dataset entry within the ...
3
votes
2answers
360 views

How to select features with NULL Geometry from Shapefiles?

I have been given a Shapefile that contains records with NULL geometry, along with records with non-NULL geometry. This situation appears to cause problems in QGIS (1.8 and 2.0) when editing the ...
1
vote
0answers
85 views

Is it possible to cut/filter all layers to an area of interest in one step?

The problem of working with a lot of data (about 100 layers). Very slow computer, rendering long. Vector -> Geoprocessing Tools -> Clip a very good tool, but replace the 100 layers is very high and ...
1
vote
1answer
340 views

How to change the color of red edit-polygon or purple snap-confirmation?

I'm having trouble seeing the purple or pink snapping confirmation when drawing a polygon because the temporary polygon is red (QGIS 2.0.1). Also the vertices in edit mode are also red. I looked ...
2
votes
0answers
56 views

How to sort legend values efficiently in QGIS print composer?

Using QGIS 2.0, I have a vertical color legend for raster values, created in the print composer. I want the values sorted in descending order from top to bottom, which appears to be the reverse of the ...
2
votes
1answer
81 views

How to make marker line thicker in QGIS?

I'm mapping railways, find that the usual cross marker line is so thin it doesn't show up in Print Composer at web resolution, and can't find any way of making it thicker, only the main line. Is there ...
3
votes
0answers
168 views

How to create a chart of the altitude of points?

I am using shapefiles with basic informations including the x-, y- and z-coordinates. I want to see how the objects (in this case points, which are finds from an excavation) are scattered along the ...
1
vote
2answers
1k views

Convert .asc format into shapefile

I've got some data from "http://srtm.csi.cgiar.org/SELECTION/inputCoord.asp" and it is in *.asc form. To process them I need to convert them to shapefile (need to merge them all into one shapefile and ...
3
votes
1answer
173 views

Converting map image to GIS

I’m very new to GIS, and I’ve been reading a lot of manuals and information, but I thought I’d ask a couple of questions here. One of my major hobbies is drawing maps of a completely imaginary ...
1
vote
1answer
97 views

How to perform intersect operations in the Field Calculator in QGIS?

How to use the Intersect function? How would I specify to REPLACE layer1.field1 with layer2.field2 WHEN layer1.geometry INTERSECTS layer2.geometry Is that feasible in QGIS?
2
votes
0answers
76 views

How to copy the contents of an attribute from one vector layer to another one that touches it or intersects it?

I have 2 layers that intersect, called layer A and layer B. Layer A has an attribute (X) that I want to copy wholesale (for the whole layer) to layer B, so that when object A1 intersects object B1, ...
1
vote
1answer
125 views

Problem loading raster QGIS 2.0

I am very new at GIS. I am trying to load a raster so that I can complete a tutorial on georeferencing. The raster file is a jpeg. However, whenever I try to load the raster, it gives me solid colored ...
1
vote
0answers
252 views

Qgis Server - Ubuntu 13.04 - Can't create a directory [closed]

I'm Portuguese (sorry about my English) and this is my first post here. It would be very useful to me, to discover how to get to work qgis server+ qgis web client. I'm a Windows user, so, I followed ...
2
votes
1answer
169 views

Batch Update Fields in Field Calculator or Model

I have a dataset of block-level census data that I clipped to an Illinois State Senate district. To update the data (e.g. for population) I'm applying an area multiplier, i.e taking the area of each ...
1
vote
1answer
220 views

How To Show Percentages By Coloring Polygons in QGIS?

I am trying to produce a map with QGIS that has counties shaded according to the percentage of people born in a US Region. For example, counties with a high percentage of people born in the South ...
1
vote
1answer
90 views

raster to ascii in QGIS

I have a raster file (DEM or .tif), but I need to transform it into a .txt file (ascii). How can I do this in QGis (Quantum Gis)? Thank you so much!
2
votes
1answer
109 views

heat map of density ratio of 2 layers of points

I have 2 vector layers of points: one with a point for each house in the city (thanks to osm.org), roughly equivalent to population one with a point for each case of cholera in the city I'm trying ...
4
votes
1answer
468 views

Using the Processing Framework in QGIS 2.0

I am writing a plugin for QGIS 2.0, and I want to use the processing framework to call some functions. When I open the pyhton console inside QGIS, I am able to call it like this: >> import ...
5
votes
1answer
293 views

Why does ManageR and rpy2 not work in QGIS (1.8.0-Lisboa)?

I have been trying to get R scripts to function and ManageR to work within QGIS (1.8.0-Lisboa). (Windows 7). Python2.7.5. Two problems indicated that R was not working in QGis. First - when I run an ...
3
votes
1answer
1k views

What expressions for QGIS field-calculator?

I do not understand what language I have to use in field-calculator and labels on QGIS: SQL or Python? And where I can find the possible script/expressions to use? in the image you can see the ...
5
votes
1answer
125 views

Finding the best locations for bee hives within a specified area (QGIS)

I would like to find fixed positions for bee hives within an orchard to ensure complete pollination of the trees. Is there a way to do this in QGIS? Example: The orchard area is 2 hectares (I have a ...
2
votes
1answer
44 views

Where did XYTools go [duplicate]

Where can I find the repository for XYTools plugin? I have tried several repositories and got messages that it was permanently removed!
3
votes
1answer
230 views

Colorify polygons in a pythonic way in Qgis

I want to addd a Layer and give the layer a color for the border and for the filling. With the code below i am possible to achieve a color for the border, but a did not found a solution to give a ...
4
votes
2answers
523 views

Sum many netCDF rasters

For the first time, I am using NetCDF data files containing daily data about soil moisture at a global level. I want to be able to obtain monthly mean value of soil moisture for each grid cell. ...
2
votes
1answer
174 views

how to remove and change qgsvertexmarker in QGIS using c++ code?

In QGIS following code is used to set marker at point A. QgsVertexMarker * marker = new QgsVertexMarker(mPlugin->iface()->mapCanvas()); marker->setColor(Qt::black); ...
1
vote
0answers
76 views

How to do dissimilarity index in GIS?

Can anybody help me to find out how dissimilarity index can be used for transport study, and is there any method in QGIS or ArcGIS for Desktop through which it can be performed ?
4
votes
1answer
132 views

Calculating a Unique ID on a Subgroup of Polygons

I would like to assign a unique ID to polygons in a dataset. The catch to my issue is that I would like polygons that fall within a polygon to have the same unique ID. My example is related to ...
6
votes
2answers
79 views

Define projection at the record level

Hopefully this isn't too dumb a question, but is it possible to define projection at the record level, instead of a whole layer or table? I want to create a "project" database for all the work my ...
2
votes
1answer
1k views

How to open a “Raster Dataset” in QGIS

I want to open a "Raster Dataset" in QGIS. In ArcMAP I can just add it like shown in the Screenshot (only the raster shows up). If I am trying to do this in QGIS. However there I don't see the ...
4
votes
1answer
147 views

QGIS 2.0.1 linking table issue, MSSQL 2008 database

I'm trying to link tables in QGIS 2.0.1 and MSSQL 2008 database. I can link them but when I try to open the attribute table QGIS throws an error and shuts down creating a *.dmp file. I saw that ...