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

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3
votes
2answers
427 views

Display two-dimensional color gradient for two different quantities

I have two overlapping raster layers. One contains quantity A from 0 to 100, and the other contains quantity B from 0 to 100. I'd like to create a map displaying both sets of data at once based on a ...
3
votes
1answer
660 views

Shortest distance from polygon centroids to a line in QGIS

To get the distance of each polygon centroid from a line, I have tried the Distance to nearest hub algorithm from the Processing Toolbox. The distances I got from the algorithm did not seem correct, ...
3
votes
2answers
396 views

Draw Vertical Line QGIS Composer

Is there a way to draw a perfectly vertical line in QGIS's Composer. I wanted to created a visual separator between two elements for aesthetic reasons. I've tried the arrow tool, removing the arrow ...
2
votes
1answer
1k views

Merge two geojson files

I have a global json files about countries' boundaries but the Russia is in two parts (two polygons). I want to merge the two parts in one, without the boundary at the middle. Is there a way to ...
3
votes
1answer
670 views

NVIS module not found in QGis

When I try to use the nvis module in Grass, QGis, pops-up a warning window saying "Module nviz not found". how can I solve this issue and use the nviz?
0
votes
1answer
108 views

Count points in a polygon that changes form (“on the fly calculation”)

I have tried to find a plugin for this, with no luck. Perhaps someone knows of a plugin that can do the following: In this project I create a lot of polygons that contain points, and the size of the ...
1
vote
1answer
93 views

Zoom to Postcode QGIS Plugin - “Postcode not Found”

I'm trying to get the Zoom to Postcode plugin for QGIS to work on my machine (Mavericks, QGIS 2.2.0) The plugin downloads fine, and when I first try to search for a postcode it alerts me that it ...
0
votes
1answer
74 views

QGIS processing does not support jpg

I would like to work with the gdal functions provided in the processing toolbox. It is easy to call: import processing processing.alglist() ...
1
vote
0answers
116 views

GIS grid linear interpolation for a given point

Suppose that I have a GIS grid. I need to do linear interpolation for a given point located inside a cell of the GIS grid. The locations and values of the vertices of each cell in the grid are ...
1
vote
1answer
137 views

How to modify existing grass gis tools and run them in QGIS?

I would like to take an existing tool of the grass tool box and modify the code to the specific needs of my task. As I´m struggling to start some kick-off would be great. How to access code? What do I ...
0
votes
1answer
22 views

Can I upload an LPA file (Long Profile) to QGIS

I have a .lpa file that I'd like to upload to QGIS - Can this be done and if so, how? Thanks!
2
votes
1answer
108 views

Creating a line from lots of easting/northing co-ordinates

I have hundreds of easting northing points which I need to join as a single line to show a route. How do I import them and get QGIS to automatically turn them into a line?
0
votes
1answer
166 views

Width and distance when using line patterns in QGIS

I am trying to make a cross hatch polygon fill (example link attached) using the values (defined by law) of 0.1mm for line width and 0.8mm for distance between the lines. But I don't get/see any hatch ...
0
votes
1answer
478 views

sub-dividing KML files

I do have a kmz file which marks the boundaries of a larger district and it's sub-districts. Still new to GIS and in the process of getting familiar with QGIS, I wonder can anyone advise me how can I ...
0
votes
1answer
514 views

DXF (points and lines) in QGIS - Doesnt import z coordinates

Trying to get to grips with QGIS, coming from a Mapinfo and Civil3D background. I have a DXF file with points (X,Y,Z) and lines. I want to open this in QGIS and use the interpolate plugin to create ...
0
votes
0answers
120 views

Can I create a cross section from points along a line without using a DEM in QGIS?

I have a set of points perpendicular to a river and would like to present a cross section of them. Like a simple graph in Excell for example, with Z as y axis and distance along the line as the x ...
4
votes
1answer
1k views

QgsMapRenderer to export current extent using PyQGIS

I am trying to accomplish PyQGIS simple map rendering via the QGIS 2.0 Python console, but end up with only a blank image. I've followed instructions of this link. My objective is to export a simple ...
0
votes
0answers
97 views

gdal_translate from within pyqgis [duplicate]

I want to use gdal_translate from within a python script in my plugin qgis2leaf. I've tried with ...
1
vote
1answer
88 views

QGIS: Turning Filter On and Off

When a filter is applied to a layer the layer cannot be edited. Is there any way of quickly turning the filter on or off without entering the Query Builder dialog box and removing the filter?
4
votes
1answer
150 views

How can values in the attribute table be refreshed automatically when a geometry changes?

I can't find a solution for auto-refreshing attribute table data. For instance, how can the data related to features of a Shapefile (e.g., the area) be updated if the feature geometry is changed.
0
votes
1answer
146 views

Qgis - unwanted offset when using raster interpolation plugin

I'm using QGis and I have a set of points with a depth attribute. I'm trying to make an interpolation using the Raster interpolation plugin (Raster -> interpolation -> interpolation). But when I do so ...
9
votes
1answer
822 views

How can I improve the speed at which QGIS 2.4 handles network data? (Seems much slower than 2.2 - even with small datasets)

I recently downloaded and installed QGIS 2.4 Chugiak on a Windows 7 64-bit machine with a quad core processor and 8GB RAM. I'm having a few problems using datasets of all sizes from a network drive - ...
3
votes
1answer
152 views

Resampling with Python console (QGIS): number of parameters

I am trying to resample two raster layers with Python console in QGIS with this code: outputs_0=Processing.runAlgorithm("saga:resampling", ...
0
votes
0answers
59 views

Changing original source projection

I am attempting to match up 2 raster layers, both a OS survey map and some independent survey data. The map I know to be in the correct position, However the survey data shows a layer extent of (layer ...
2
votes
0answers
182 views

Exporting SHP files into Autocad readeable files

I have a full water supply network drawn in a shapefile which I created using Qgis 2.2.0. Now I need to export it into a format that enables me to open it in AutoCAD. I am trying to export it as a dxf ...
1
vote
0answers
427 views

How to force geometry type in (WFS) layer in QGIS

I have an external WFS source serving mixed geometry types - in other words, I have no control of the source. When adding the layer QGIS sets the geometry type to line and thus I am unable to style ...
1
vote
5answers
2k views

Solutions for uploading maps to GPS (forestry maps: roads, trails, hydro, polygons)?

I'm using a QGIS 2.2.0 Valmiera on a Windows 8.1 system Desktop. I'm a forester and I would like to have a cheap solution to load maps into the handheld Garmin 60, 62 or 64 series GPS. Free would be ...
0
votes
1answer
157 views

how to select line segments not overlapped by other layer's lines

I have two shapefiles of forest roads (mostly dirt) from different sources, covering the same area. The goal is to build one shapefile of roads that is the composite of the other two. Layer A is ...
2
votes
1answer
372 views

How to use the MMQGIS plugin through the Python console?

I know how to make Hub Lines using the GUI, I want to know how to do the same using the Python Console, a tutorial would be great. Thank you
5
votes
0answers
7k views

Open Layers Plugin and QGis 2.4 [closed]

I have installed Qgis 2.4 with the stand alone installer and the OSgeo4w too on three different computers. Two have win7 64 and one vista 64. It seems that the Open Layers plugin does not work ...
1
vote
0answers
192 views

Is there a way to QGis read an SDE.ST_GEOMETRY field?

this is the type and name that Qgis displays for me when I connect with a oracle table,it is not displayed as a geo column, there is a setting I'm missing? Can Qgis Read this type of data?
0
votes
1answer
674 views

Using Union on multiple shapefiles to output single result

Using QGIS 2.2 and Python, I would like to use the Union algorithm on multiple shapefiles (contained in a folder TEST) which would then produce single shapefile containing all the data. Currently ...
2
votes
2answers
434 views

How to switch to edit mode vector layers, in pyqt application based on qgis?

I do QGIS based application, I need to implement the ability to modify the geometry of vector layers in manual mode (editing nodes), how to do it?
0
votes
0answers
385 views

How to extend lines from “station line” plugin in QGIS

I'm trying to create cross sections using the station line plugin (and then import them to HEC RAS). But I can't seem to create lines longer than 99.99 meters from each side of my river line. Is this ...
2
votes
1answer
160 views

Low quality legend symbols in QGIS

The legend symbols in my QGIS map composition render very pixelated, like this: However, they render fine for actual point data. They appear this way within map composer, when printing, and when ...
0
votes
1answer
140 views

QGIS copy and paste error: “no features could be successfully pasted”

What does this error message mean, and how can you get more info on what might be the cause? "no features could be successfully pasted" (or more generally, not all of the selected items could be ...
1
vote
1answer
100 views

Why is interpolation adding too much heat

I am interpolating geo data using qgis. The data is in the form of lat,lon,count. The path of the collected data is shown as a mostly transparent line. The resulting heatmap it produces is shown. ...
0
votes
1answer
217 views

from Qgis 2.2 to Garmin Base Camp: how to get rid of the white frame?

I have geo-referenced a raster map in QGIS 2.2 (with the georeferencer plugin) and I can also create a kmz file for my garmin (Dakota20) with GarminustomMap. However the kmz file, as imported in Base ...
2
votes
1answer
237 views

How to exactly georeference in QGIS

When I georeference a raster image in QGIS, it's always a bit displaced as in the attached image (the cyan polygon is the template, the red border is the georeferenced image), although I try to set ...
3
votes
1answer
260 views

Maximize clusters of points from coordinate data

So I am definitely new to the GIS world, so bear with me if I don't know the best way to articulate my problem. That said, I am ready to learn, I would definitely welcome any direction that you all ...
1
vote
2answers
3k views

“Missing dependency.This algorithm cannot be run :-(” QGIS + GRASS Windows 7

Windows 7, OsGeo4W pack installed including QGis 2.4.0 and GRASS. I Qgis when i try to execute a GRASS geoprocessing algorithm i get this popup: "Missing dependency.This algorithm cannot be run :-( ...
3
votes
0answers
361 views

How can I label the pie charts in QGIS so the labels are written under the diagrams?

How can I label the pie charts in QGIS so the labels are written under the diagrams? My pie-charts are representing localities: such as villages, towns, cities. So, I want that their names appear ...
0
votes
0answers
427 views

Why can I not publish from -QGIS Geoserver plugin?

I am following the tutorial at http://qgis.boundlessgeo.com/static/docs/quickstart.html and I get to the step "To publish the project as it is, just select the QGIS project entry in the OpenGeo ...
1
vote
3answers
230 views

How to complete the roads output of PostGIS?

I converted the file I exported from OSM to PostGIS using osm2pgsql. I have opened the table's outputs to QGIS and I saw data are not complete compare to OSM editor view. Most of the roads are broken ...
10
votes
1answer
675 views

How to call the interpolation plugin from the python console?

I would like to call the QGIS interpolation plugin function (TIN method) (Raster->Interpolate) from python console. I can't find the corresponding function within QGIS API or within the ...
2
votes
1answer
235 views

QGIS contour plugin exception struck help

I am a fisheries biologist and I am just getting started with QGIS. I took a few GIS classes in college so my GIS knowledge is not extremely high. On to my question. I am trying to make a depth map ...
3
votes
1answer
510 views

How to open, modify and save a QGIS project with PYQGIS

I need to create a stand-alone script for opening a QGIS template project, modify a layer data source, export the Composition and finally save the modified .qgs project into a new file. So far I have ...
1
vote
0answers
74 views

PostGIS points to multipoint error

I have a table on PostgreSQL 9.2 ("POSTGIS="2.0.1 r9979" GEOS="3.3.3-CAPI-1.7.4" PROJ="Rel. 4.8.0, 6 March 2012" LIBXML="2.8.0""). This is it: CREATE TABLE nearest_point ( id_nearest_point serial ...
0
votes
0answers
999 views

PyQt resources file to display images on QGIS custom feature form

I am having issues creating a PyQt4 resources file to display images in my QGIS 2 custom feature form using Windows XP. These are the steps I followed: -Added QLabel and clicked "choose resource…" ...
0
votes
1answer
243 views

PyQt QTableWidget for QGIS python plugin: infinite loop issue

I'm using PyQt4 and Python 2.7 to develop a plugin for QGIS 2. I have QTableWidgets used to display/compare existing information in the database with newly entered information pertaining to the same ...