Tagged Questions

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

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10
votes
5answers
10k views

Changing CSV layer attribute value from text to number in QGIS?

I read in a CSV file for linking to a .shp file. All the variables that are just numbers came in as text. How do I change the text variables to numeric in QGIS?
2
votes
1answer
378 views

Bathymetry of Quarry Lake in QGIS

I've been asked to do a project that maps the bathymetry of a quarry lake. It seems like I've seen a feature in QGIS that would help with this if I took a bunch of depth points in the lake. Any ...
9
votes
1answer
6k views

How to run a simple python script for QGIS from outside (e.g. Sublime Text)?

I would like to run a few small and simple python scripts for QGIS (Mac) from "outside" of QGIS. With outside I mean in this context, either the normal os command line (terminal.app) or even better, ...
5
votes
2answers
920 views

How to automatically add vertices to lines every x meters?

I've made a vector grid using lines; the grid coverage is 100 km x 100 km and the lines are at vertical and horizontal intervals of 1000 metres. Each line in the grid is defined by two vertices, one ...
5
votes
1answer
541 views

Custom Geographic Transformation on QGIS

Is there a way to create a custom geographic transformation with specifics parameters in QGIS like in ArcGIS? Okay, I want to tranform SAD69 system into WGS84. Well, I'm in doubt because in ArcGIS ...
1
vote
0answers
276 views

QGIS Web Client Setup mapserv error

I have my web map up and running and am now trying to clean up a few recurring errors in the qgis-web-client-error.log. The error in question is: [error] [client 123.456.789.1] script not found or ...
5
votes
1answer
2k views

Setting up an application in QT Creator that uses QGIS API

I am a 15 year veteran of Java making my first entry in to C++ applications. I have a specific need to develop a desktop application that produces graphics type output as well as displaying imbedded ...
6
votes
2answers
5k views

How to draw a Circle with a set radius?

I have a site and want to draw an indicative line in a 5km buffer around the centre of the site. So I want to draw a circle with a radius of 5km. I have a tool for drawing circles and ellipses and ...
2
votes
2answers
336 views

What is better for spatial data analysis? REST or SOAP?

I am working on agriculture forecasting project. It is the integration of SOA, web services, ontologies etc. What is better for spatial data analysis ? REST or SOAP ? WMS, WFS are used but either use ...
8
votes
6answers
4k views

How to get “.GDB” Esri File Geodatabase in QGIS for MAC OSX 10.6?

I understand there are programs like OSGeo4W that allow windows users to work with File Geodatabases, but is there something similar for Mac OSX?
0
votes
1answer
718 views

How do I get feature count of a QgsVectorLayer?

I'm using this code to get features from QgsVectorLayer QgsVectorDataProvider* provider=theVectorLayer->dataProvider(); if(!provider) { return; ...
3
votes
1answer
297 views

Impossible to open the .qgs file I've just saved with QGIS 1.8

I'm using QGIS 1.8.0 on Mac OS X 10.6.8 (last stable version of QGIS I downloaded yesterday). After working yesterday and this morning on it, I'm trying to open it again, and QGIS asks me the ...
1
vote
1answer
3k views

How to create a circle with specific radius? [duplicate]

Possible Duplicate: Conflicting measurement units with buffer ftools I have a shapefile as input. How could I create a circle with a radius of exactly 500 meters, using QGIS?
5
votes
2answers
2k views

How to add links to PDFs in a Shapefile?

I have a problem. I want an attribute in a shape file named "Link" to add. The works are all fine. But then I would like to add a link in my directory. This link accesses a PDF. Now, this PDF is not ...
1
vote
2answers
312 views

Routing issues with pgrouting

I was using the pgrouting plugin to display the shortestpath. I used the plugin as suggested by underdark to display the shortest path in qgis. My source node is 283 and my target node is 172. When I ...
1
vote
3answers
647 views

can QGIS for Mac OSX 10.6 handle (both read and generate) GeoPDF files?

I would like to know if QGIS for Mac OSX 10.6 can handle (both read and generate) GeoPDF files. Can anybody help ?
2
votes
1answer
466 views

Plot the nodes of the shortest path found by dijkstra algorithm

I am using qgis and pgrouting plugin to find the shortest path between two nodes and display the route. Currently, the plot shows the shortest path. However, I also want to know which nodes the path ...
0
votes
0answers
171 views

Installation does not work

I tried to install QGis on my computer (Windows XP Professional) but it does not work at all. I do get the installation wizzard and I can complete that, but nothing happens. After completion, the ...
2
votes
2answers
185 views

Determine the furthest driving distance from a road layer to the nearest point of a point layer using OSM/QGIS

In a specific geographic area, I have a road layer and roughly 30 points dispersed around the geographic area as part of a point layer. Both layers are in SHP and PostGIS formats. The records from the ...
11
votes
2answers
2k views

How to concatenate labels in QGIS?

I'm using QGIS 1.8 on windows XP machine and I try to do a concatenation of several fields to label the names of my local roads in the attribute table, but I can not find the correct syntax. The first ...
2
votes
2answers
297 views

Unable to open QGIS after Installation [closed]

I have a Windows Vista (32 bit) computer. I tried installing and reinstalling (by uninstalling the software first) QGIS 1.8 a few time then went to version 1.7.4 and still encountering the same ...
1
vote
1answer
132 views

Node Visibility Within Layer

Is there a way within QGIS to hide/display (freeze/thaw) an individual node feature within a layer or does this control only exist at the layer level.
4
votes
3answers
1k views

Is there any way to add a google maps layer in a qgis web client project?

Is there any way to add a google maps layer in a qgis web client project? I made a qgis project using a google maps layer from OpenLayers Plugin. In my desktop project, this layer works fine. But ...
1
vote
1answer
484 views

How to get a signal when the geometry to a line in QGIS is changed

I am working on a plugin in QGIS and want to get a signal when the geometry to a feature(in this case a polyline) in my layer is changed. For example if I use the node tool to drag one of the nodes. ...
1
vote
4answers
3k views

ECW on QGIS 1.8 (Ubuntu 11.10)

I'm trying to deal with an ECW file with QuantumGis 1.8 Lisboa, on Ubuntu 11.10. Obviously it tells me that .ecw is not a supported kind of file on QuantumGis. I have tried to install all the ...
5
votes
1answer
2k views

How to create a hole in a polygon in QGIS?

I'm trying to use the tool "delete ring" in order to create a hole in a polygon. The geometry of the hole is another feature of the same shapefile I cannot manage to delete the part of the polygone. ...
1
vote
1answer
469 views

How to fix Exception: forward transform failed with error: latitude or longitude exceeded limits

Export to vector file failed. Error: Failed to transform a point while drawing a feature of type 'Dingalan_Brgy_Boundary'. Writing stopped. (Exception: forward transform of (5731.78, 29676.2) failed ...
3
votes
1answer
450 views

Area overlay of census on Zip Code

I have census block data polygons. I want to overlay them over Zip Codes (larger polygons) in order to estimate the population in the Zip Codes. Or overlay buffers around toxic waste sites over census ...
3
votes
1answer
232 views

heatmap plugin slow/unresponsive in QGIS 1.8

I am trying to use the new heatmap plugin to create a heatmap from about 10k points. When I enter the parameters and start the process , QGIS becomes unresponsive. I don't get a progress bar or a ...
4
votes
4answers
4k views

Is there a Rotate Tool in QGIS?

I can see the move tool. But coming across versions, i did not see any Rotate tool in Quantum GIS. As a hardcore feature editor myself, i have found it rather difficult. Am i missing something ...
4
votes
5answers
6k views

How do I create a line between two points with a common field?

Does anyone know how I could create a line between two points that have a common code? For example: I have the start and end point of a pipe as a lat/long for a network of pipes, each with a ...
0
votes
1answer
976 views

QGIS Azimuth and and Distance Plugin

Where do I find this plugin? ( I am on v. 1.6 - it does not seem to be installed and I could not find it with the python plugin installer). -Robert
3
votes
2answers
822 views

Maki Icons to Qgis

Does anyone know how to import Maki icons to qgis? Maki Icons
2
votes
1answer
165 views

QGis - Plugin libraries

I need to develop a couple of qgis-plugins. I made some promising first steps and completed a few easy plugins. Now its time to move to more complex plugins which need to import several tool-classes I ...
5
votes
1answer
730 views

QGIS - export a project with dependencies

I was wandering if there was a way to save a specific project with all layers as dependent files to make it easy to share with collaborators. for example, create a zipped or non-zipped folder ...
2
votes
0answers
366 views

Mean coordinates in QGIS

I am using QGIS v 1.7.4 for MAC and I am trying to calculate mean coordinates for a set of points using ftools. To calculate my result I am going to Vector -> Analysis tools -> mean ...
1
vote
2answers
427 views

Any luck with photo2shape?

I have had variable success with photo2shape in QGIS. I can't figure out what is the success/no success prerequisites. Any thoughts? Currently I have a directory with all 334 photos having geotag ...
2
votes
0answers
68 views

System Requirements for Quantum GIS [duplicate]

Possible Duplicate: Looking for system specifications for a modern GIS workstation I have been using the program to make maps to include in my reports over the past year or so. It is ...
5
votes
1answer
381 views

How do I avoid text field truncation when saving a table join?

Using QGIS I've joined tabular text data (all in fields of less than 255 characters) to a shapefile via a CSV file. All looks good in the joined table but when I save to a new shapefile to make the ...
1
vote
0answers
322 views

Copy ArcGIS symbol files to QGIS

Is there a way to copy the ESRI symbol files for use in QGIS. if not id there a resource to get various svg files to use in QGIS? DIfferent linetypes as well?
3
votes
2answers
2k 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. ...
1
vote
0answers
2k views

Error when importing shapefile to Postgis database

I was trying to import shp to postgis database and i get the following error: Importing with configuration: adresy92, public, geom, C:\Users\tomek\Desktop\adresy92, mode=c, dump=1, simple=0, ...
15
votes
9answers
22k views

How to install QGIS on Ubuntu 12.04?

Has anyone had any luck with getting QGIS working on Ubuntu 12.04? I have tried the stable and unstable versions and with not luck. I also get the following: "Some packages could not be installed. ...
2
votes
0answers
114 views

How to send data from my application to QGIS?

I have an application that makes analysis on maps . After making analysis I have new map in my application. My application doesnt use QGis API. How can I send results back? Should I construct ...
0
votes
1answer
687 views

How are .mif files loaded to QGIS?

I have downloaded sources of Qgis 1.8. I would like to know how it accepts mif file. As I have learnt after choosing add VectorLayer. Method addVectorLayers is called. Then openvectorlayer dialog ...
9
votes
2answers
308 views

Options for a historic Web Map?

EDIT: I'm an intern at a small local history museum. We have a budget of $0. Project overview: I've got a bunch of old paper maps. When I say old, I mean 1800s and up. They've been scanned into ...
2
votes
1answer
824 views

Extract all the intersections from a polyline shapefile

I would like to extract all the intersections from a polyline shapefile and print their addresses as text using either ArcDesktop or Quantum GIS, is there a straightforward way to do this? My ...
3
votes
1answer
327 views

Why does QGIS Polygonize ignore the no data value?

I'm running into an issue georeferencing a number of PNG image files. The files simply contain an image where each pixel is either transparent or a single color, forming a coverage mask. In the past, ...
4
votes
1answer
852 views

merge selected features and programming

I have a shape file with UK districts and unitary authorities. In the past, using commuting patterns, I worked out a new geography which is close to travel to work areas. I now would like to create a ...
4
votes
1answer
249 views

QGIS Globe UnsupportedOperationException

My QGIS Globe is not working: After starting it, that massage pops up in a endless loop: UnsupportedOperationException: GeometryGraph::add(Geometry &): unknown geometry type: ...