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

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3
votes
1answer
3k views

Trying to install QGIS - missing 1.11 GDAL

I just spent the last n hours working on this, and still haven't gotten anywhere, so I'll throw it to the group. I see that other people have asked about this here and here, and I'd be happy to take ...
3
votes
2answers
359 views

Merging raster and vector not working

I have 1 vector layer (counties) and 1 raster layer (population density). I have tried merging these two, so that I can examine population density within a county, but I have had no luck. It just ...
6
votes
1answer
197 views

How to create a storm swath map?

I can't really find the words to explain what I'd like to achieve so I attached a picture. The top picture was made of two layers, the layer with circles was made/styled using the instructions from ...
1
vote
3answers
153 views

How to delete horizontal lines from a vector grid?

I have a 250ms vector grid which covers an area of 88 Sq.kms. For surveying purpose, we would like to retain the vertical lines alone. Is it possible to delete all the horizontal lines from the grid ?
1
vote
0answers
24 views

Free And Open Source Software Tools to orthorectify Pleiades imagery [duplicate]

Are there Free And Open Source Software Tools to orthorectify Pleiades, Worldview And Quickbird imagery as we do with COST tools such as ERDAS Imagine, PCI, ENVI, etc.?
2
votes
0answers
369 views

Postgis / QGIS Snap Point to Line

I'm trying to snap points to lines in postgis for use in QGIS, but cannot get it to work. I have one line in my line table (although it was created by merging multiple lines together) and about 600 ...
4
votes
1answer
127 views

Adding super/sub script in QGIS text annotation?

How can I add a super/sub script in a QGIS text annotation? For example, 44.95 mi^2.
3
votes
0answers
827 views

QGIS 2.4.0 Mac Yosemite compatibility

I just upgraded to the Beta 2 version of MacOS 10.10 ("Yosemite"). I'm getting an error when I try to "drag and drop" shape files into QGIS. I'm running QGIS 2.4.0, GDAL 1.11, and MATPLOTLIB 1.3.1. ...
3
votes
1answer
289 views

QGIS way to import OSM/Google Maps but remove or exclude extraneous areas, limit geographically the use of OSM

GIS Newbie question, perhaps: But I am looking to place an Open Street Maps/Google Maps layer underneath the rest of my shapefiles for referencing purposes. Let's say for instance, that I am looking ...
3
votes
3answers
1k views

How to measure correct distances in a project with OpenLayers background?

I have 3 lat/long points as follows: A = {35.257246,139.721256} B = {35.256541,139.721491} C = {35.256326,139.7203271} 1) Measurement result by Movable Type Scripts: By using the distance ...
1
vote
1answer
468 views

How to use two different Python versions (3.4 and 2.7) for QGIS scripting?

I´m intending to learn scripting with python in QGIS, but I have a couple of questions. I'm using Python 3.4 for learning which is installed in my laptop, but QGIS is using Python2.7 How could I ...
1
vote
1answer
546 views

Box cropping shapefile based on particular latitude and longitude using QGIS? [duplicate]

I have a shapefile and I need to crop/clip it based on a rectangle of particular latitude and longitude using QGIS. If it is possible, how do I do that?
3
votes
1answer
334 views

Conflicts while installing postgresql9.3-postgis2.1,QGIS and gdal-bin

I want to use postgresql9.3-postgis2.1 and gdal-bin parallel . I have refer instruction here for installing postgresql-9.3 on ubuntu 12.04. I have install qgis from here While installing gdal-bin it ...
1
vote
0answers
59 views

QGIS fTools very slow adding random points?

I am currently on windows 8.1 qgis 2.2 and almost everything I am trying to do using ftools is too slow. For example: using divaGIS world countries layer (.shp) when I try adding 500 random points ...
4
votes
1answer
1k views

Draw lines between two points in QGIS

I have an excel (Fig) which has both X & Y in projected coordinates (WGS84/UTM). Is it possible to draw lines between the X & Y in QGIS ? I've tried to create points based on X,From_y and X,...
2
votes
2answers
187 views

Parse Field to Select Records

I wish to select records based on the NRN attribute in my dataset : "NRN" IN ('1','2','23','31') Some records have multiple values in the NRN field separated by the underscore character. For ...
2
votes
1answer
330 views

How to add buttons to QT ui for qgis feature forms to loop through attributes?

I'm looking for a bit of guidance. I'm happy creating a standard feature form using QT designer (as excellently documented here) for QGIS but I was wondering how you add a forward and back button to ...
-2
votes
1answer
297 views

Identifying projection for shapefile with unknown coordinate system, no z values and no measures? [duplicate]

I am attempting to create a GIS Project with multiple Brazilian cities. I have been collecting, and am interested in, shapefiles that delineate the neighborhood boundaries of said cities. One city's ...
2
votes
1answer
70 views

How to cover a number of points with disks?

I have to cover some points with disks. These disks are not of a fixed size, they have to constraints: a maximum diameter, and a maximum number of points covered. I would like to minimize/...
1
vote
2answers
1k views

How to create spline in QGIS [closed]

I want to create spline in QGIS. I have tried to use Cad-tools - Create spline line\poligon but I can only draw it and can't save. What is wrong I am doing? Is there other way to create spline?
2
votes
0answers
466 views

QGIS 2.4 Processing (Zonal Statistics) error

In QGis 2.2 all my models (processing model builder) are working fine. When I start the same models in 2.4 I get errors like this: Prepare algorithm 5: Zonal Statistics Running Zonal Statistics [...
2
votes
2answers
497 views

Tiled raster image to be placed in an OSM/ Leaflet.js map

I have a mapoverlay in a custom projection which I need to add as a layer to an Openstreet map within a website. Since I was not able to change the projection earlier, I decided to manipulate the ...
1
vote
1answer
189 views

How to scale with radius attribute

new user of QGIS. I would like to style vector data based on an attribute (radius). The actual unit is in nautical miles. I don't want to use size-scale field or buffer to style the point rather I ...
2
votes
1answer
292 views

Why is feature.geometry() None in my user-defined expression function?

I'm trying the user-defined expression functions for QGIS, as listed on Nathans blog: http://nathanw.net/2012/11/10/user-defined-expression-functions-for-qgis/ I always get the feature.geometry() as ...
1
vote
0answers
56 views

My map is little bit off

I am pretty new in GIS things and i have been learning how to use QGIS. Most of the maps are fine, but yesterday I went to GIS center at my University and I got the maps of my country that I will be ...
4
votes
2answers
683 views

How to set Zero values to NULL using QGIS pycalc?

I'm using QGIS 2.4 pyclac and windows 7 OS. I have columns that should show NULL value but instead of that they show Zero (0) value, I need those fields to be NULL. This far I have seen a script that ...
1
vote
0answers
79 views

Scaling features based on an attribute

I would like to scale polygon features by a specific factor I have calculated for each feature in a feature class. I know of the Scale tool, however it only allows for manual entry of a scale factor ...
0
votes
1answer
206 views

How to set image size with Image Map Plugin on QGIS 2.4?

I use QGIS 2.4, but I have noticed that the "Set Map/Image Size" feature on the HTML Image Map Plugin no longer seems to work. No matter what you set the "Set Map/Image Size" for, your image will ...
2
votes
0answers
253 views

3D visualization of terrain data and orthophoto using GRASS NVIZ via QGIS

How can I make 3D visualization of terrain data and orthophoto using GRASS NVIZ via QGIS? I am quite new with GRASS. I have only managed to get a 3D view of the terrain so far.
1
vote
1answer
43 views

gdaltools in qgis v2.4?

Where's the GDALTools plugin for QGIS 2.4? It's not listed in list of available plugins, and it's seemingly not installed out of the box. Is it just that it's not yet compatible?
1
vote
0answers
54 views

How to install the QGIS Raster Lang plugin?

I´m trying to install the rasterlang plugin for QGIS. I tried several things on this website but it seems to be quite complicated because I need to install binary files and other files. The idea ...
1
vote
0answers
449 views

QGIS plugins - how to use a custom behaviour on right click and actionPan on left click?

I have been struggling with this problem for quite a long time. Here we go : I implemented a maptool that draws a red cross on the point that is being right-clicked on. There are good how-tos, such ...
1
vote
1answer
72 views

Performing transformation from GHANA GRID to WGS 84 using QGIS?

I have a shapefile which was referenced using Ghana's grid system. I imported it to QGIS and specified WGS 84 but the coordinate bar still displays the Ghana grid values in the coordinate bar. Is ...
2
votes
2answers
124 views

QGIS Processing - Additional Creation Parameter for GdalWarp

I am having a hard time getting the "Additional Creation Parameters" to work when using GdalWarp through the processing toolbox. I am trying to set the nodata value to 0 for the output raster. ...
8
votes
4answers
2k views

Unable to zoom beyond scale of 1:2,256 in QGIS?

In QGIS, whatever might be the source, I couldn't zoom beyond the scale of 1:2256. Whether it's a raster or vector, result is the same. Does anyone know how to fix this ? Edit: Thanks to Chris. ...
2
votes
1answer
258 views

Rasterizing Contours - How to remove 0 values

I want to convert vector contours to a DEM. From other posts, I wanted to utilise the Grass r.surf.contours tool. Initially I converted the vector contour layer to a rasterized contours using the "...
2
votes
2answers
1k views

Date-format conversion

I'm using Time Manager and QGIS 1.8.0 and I am stuck at date-format conversion. Time Manager needs Gregorian format YYYY-MM-DD HH:MM:SS.ssssss in text field and I have thousands of records in "month/...
3
votes
1answer
1k views

How to install Apache Web Server from OSGeo4W?

Good morning, I'm trying to create a QGIS web client on my Windows 8 But with OSGEO4W not appear the option to make Apache installs Web Server, as of this writing in several tutorials and ...
3
votes
2answers
185 views

Why is the OSM map itself is not visible in my qgis window?

I'm new in working with QGIS. I have tried to download an OSM map of Rome and its surroundings into my QGIS. As far as I am concerned, I have followed each step which I could find on various websites....
4
votes
1answer
635 views

Using Engineering symbols (*.svg) in QGIS?

QGIS looks straight forward except for the symbols or icons. I have created SVG symbols and when I place my pointer to the obvious blank areas in the symbol library a pop-up says that my symbol is ...
0
votes
0answers
42 views

Where can I find “QGIS Training Manual” data? [duplicate]

I can't find data for this lesson in Quantum GIS: 9.4 Lesson: Supplementary Exercise. Can anybody help me?
0
votes
1answer
222 views

Gdal_sieve not working?

I'm using the Sieve command within QGIS (Raster > Analysis > Sieve), but when I run the command with any variation of parameters, it completely changes the histogram of my raster data from between -0....
2
votes
1answer
566 views

Best Landsat band for forest classification?

Using Qgis and the Semi-Automatic Plugin for Classification, which are the best Landsat bands to use to classify trees species (in central Argentina)? In Landsat 5, 7 and 8?
2
votes
0answers
218 views

Setting up qgis web client

I have a problem with setting up a qgis web client on remote server. I set it up on localhost and it runs smoothly, but when I done exactly the same on remote server it is just not working, even a ...
2
votes
1answer
488 views

PyQGIS - Start/Stop Editing with data Provider - Commiting changes

I want to edit a specific field for a QgsVectorLayer, within a QGIS application. I am facing inconsistent results from my code, ie: changes are not alway commited. Please could someone point me to ...
4
votes
1answer
212 views

How do you set the position of a plugin window when you start the plugin?

I'd like to set the position of a plugin's window or dialog relative to the map canvas frame. For example, if I start a plugin, I want it to appear somewhere in the left upper corner of the map ...
3
votes
0answers
353 views

How to calculate percentages using QGIS field calculator expression?

I am new to QGIS. I am wanting to calculate a field using other fields and some operators. Here is my expression: case When "RVM_CAT" = 'B' OR "RVM_CAT" = 'C' Then ("PC1" /100) * "RE_ha" When "...
1
vote
1answer
69 views

Contour generation using Interpolation - Correcting edge Effects

I utilised the Interpolation feature in QGIS to prepare contours from a DEM I had generated. Sometimes when contours intersect the edge of the DEM area, they run along the edge for some distance. ...
1
vote
1answer
566 views

How to add new columns with attributes in existing Qgis layer?

How to add new columns with attributes in existing Qgis layer? Doing the "same thing" here described
3
votes
1answer
239 views

Reverting QGIS to version 2.2 from 2.4

I have QGIS 2.4 installed on a machine running Windows 7 64-bit "by accident". I was using 2.2 and when I added some package(s) it also installed the 2.4 version. Can anyone provide some advice with ...