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

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3
votes
1answer
56 views

What causes OTB pansharpening ERROR Inputs do not occupy the same physical space?

When I try to use the OTB pansharpening tool an error comes up and I don not really know what the problem is. I have a RGB and a Band8 map (both from Landsat8) which I want to use for the tool. All ...
0
votes
0answers
8 views

Changing attributes of multiple features in a specific area

I have a data of road network stored in Oracle 11g database. I want to select a small area of the network and change the attributes of all the affected roads segments in that area (assuming that the ...
6
votes
2answers
5k views

Create a polygon layer from point data

I'm currently using QGIS 1.8.0 I would like to create a polygon layer from a point dataset, where the size of the polygons relates to the resolution of the grid reference. The ultimate aim would be ...
0
votes
2answers
315 views

QGIS regular points around each polygon in a layer (vs ALL polygons)

I have a number of buffered points (some where polygons intersect & are dissolved. I'd like to create regular spaced points grid around EACH polygon -- not ALL polygons. When I do Vector -> ...
1
vote
1answer
39 views

Construction of a square grid from a given centre (lat,lon) and direction of the sides

Let us consider a point (longitude, latitude) on Earth (location). How to construct a square grid around this point (taking this point as the centre of the square or intercept of the two diagonals) ...
2
votes
3answers
128 views

Why script works on my computer but not on another?

The script below works perfectly fine in my computer. But when running the script on another computer, I receive an error: Error: Algorithm not found The computer has similar specifications to ...
1
vote
2answers
204 views

Using Qt Designer to Create a Form in QGIS that can search for a specific point in a layer

I would like to ask if you can create a form in Qt Designer to create a form that can search for a point on the map using data that the user will provide such as the Name. I am currently creating a ...
2
votes
1answer
319 views

Help with scripts for processing raster files with the raster calculator in QGIS

I am trying to process some raster files using python scripts in Qgis 2.20, and I have been having trouble finding any documentation on using raster calculator in scripts being run in the processing ...
1
vote
1answer
34 views

QGIS Google Maps Coordinate System

I have some Points in Shapefile with BC Albers Coordinate Syetem and I need to Project them to Google Maps Lat and Long. I tried to do this by using WGS 84 / Pseudo Mercator EPSG: 3857 and ...
2
votes
1answer
1k views

How to evaluate raster calculator expressions from the console?

How can I execute from the console an expression that should be used with the raster calculator? I'm searching for something like this: qgis.someRasterCalcClass.evaluate("boh@1 + boh@2", ...
3
votes
2answers
666 views
+100

Split Lines at Intersection of Other Lines

I have two line layers (roads and contours in this example) and I would like to split the roads layer every time it crosses/intersects a feature on the contour layer. I can't seem to find a tool that ...
1
vote
0answers
8 views

Coloring multilinestringzm M values in QGIS

I have output from a geophysical technique that produces X,Y,Z and scalar value for millions of points, which have been stitched together appropriately (by networkx if it matters) into ...
2
votes
0answers
23 views

QGIS on UHD screen

I've got a new laptop that came with a 4k UHD screen. The GUI on QGIS doesn't scale well making most of the menu elements too small to easily see. Is there a way to change the scale of the gui?
0
votes
1answer
197 views

Pull pixmap image source from ui edit text in QT

I'm putting together a custom form for QGIS identify using Qt Designer. One attribute has a file name to the accompanying photo of the feature. I'd like to have the photo label in the form grab the ...
1
vote
0answers
19 views

Convert mapinfo styles toward qgis styles

Up to now, I has worked with mapinfo. I have a big vector layer (points) with a complex symbology. For several days, I gave up mainfo for qgis. Is there a way to converting my mapinfo files (.tab) ...
2
votes
0answers
29 views

Computing Shannon-Weiner biodiversity index using QGis

I wonder if anybody has some experience in calculating biodiversity index (such as Shannon-Weiner) using QGis. I am also interested for similar experiences using R scripts within QGis. The analysis ...
1
vote
0answers
27 views

Add field and number fields of different shape files

In my project I have 3 different shape files (shape1, shape2, shape3). All of them should get a new field (add field to attribute table). In this field I need to have a number (for shape1=1, shape2=2, ...
3
votes
1answer
42 views

Making QGIS buttons and my Plugin button mutually exclusive

I've added a toolbar to the QGIS main window and I've added some checkable buttons to the toolbar. How can I make my checkable buttons untoggle QGIS default toolbars' checkable buttons? That is, ...
3
votes
1answer
62 views

Getting random values from geometryType() in a standalone PyQGIS script

I am asking this question based on the result I received from this earlier post. The following script only works if I set geometryType() == 3 as that is what is being printed out in the Python console ...
1
vote
1answer
36 views

How to get value and store it in a variable from a line edit or text edit in pyQT?

How to get value and store it in a variable (in main python plugin) from a line edit or text edit box that were created in QT designer ?
0
votes
1answer
31 views

How can I merge two lines in 2.6.1-Brighton?

When I try to merge two lines selecting them and using the Merge Tool in the Advanced Editing Menu I get an error which says that merging these lines would result in an incompatible geometry for this ...
2
votes
1answer
37 views

Specific renaming of elements in Attribute table failing until closing and reopen attribute table

Well the title tells it already. I have a column name and 100 objects. I have given them all a name. Now I mentioned that I have written some wrong of them. So I tried to correct them by double click ...
1
vote
0answers
14 views

How to make both the mouse button click event to do the different function

I am using the canvas event with mouse button click events. def canvasReleaseEvent(self, event): if event.button() == QtCore.Qt.LeftButton: print 'The left button event is',event ...
1
vote
0answers
7 views

Importing ArcGIS and/or CAD template into QGIS print composer…Can it be done?

ArcGIS is used very widely in Environmental consultancy and the print/map templates used for reports are usually passed around in an MXD or CAD file format. Unfortunately we cannot afford ArcGIS and ...
3
votes
1answer
19 views

Copying features to new location

I want to copy some features from one layer and paste them onto another layer with all their attributes, but in a different geographic location. Is this possible? These are very small features a very ...
2
votes
1answer
11 views

CRS dialog no longer opening

I'm new to QGIS, so supect this is trivial, but it has frustrated me for the last hour or more... Last week whenever I added a csv as a layer once I'd filled in the first dialog it automatically ...
1
vote
0answers
11 views

Selecting elements from network with shortes path in QGIS?

I have a network of vector elements (let´s say 70 elements) that are connected in each node. Actually, it is a pipe network built with the help of GHydraulics ...
5
votes
1answer
154 views

How to convert PostGis Table (Grid data) to Continuous field using Qgis?

I'd like to transform my Gridded Layer (generated form a PostGIS table of points) to a continuous and colored layer. How could I do this with Qgis or any other program?
2
votes
1answer
96 views

Obtain Longitude/Latitude Values and Export Data From QGIS

I have a CSV file with address data elements (Street# and Name, City, State, Zip). I'd like to be able obtain corresponding X,Y coordinate for each of the address? How do I achieve this using QGIS? ...
0
votes
1answer
96 views

What expression returns data defined color from a color field eg: (30 50 40 10) using color_cmyk

Hi I have a geology plan with a base color field. I need to write an expression in the data defined color option using "color_cmyk" command. I can not seem to get the expression written correctly. The ...
2
votes
1answer
26 views

How to get the attribute list of a point that is clicked on the map

I would like to double click a point on map and directly getting to its attributes. I'm too lazy to go through the list auf 400 items, just to find it. Is there any way to do this?
0
votes
0answers
28 views

Matplotlib downloads to override folder

Just completed install of QGIS (2.0.1 Dufour) on a Macbook Pro running on Mavericks via Kyngchaos download page. However, when downloading Matplotlib for the install, while everything ended up the ...
3
votes
1answer
86 views

How to get User and Password of a PostGIS layer from PyQGIS

I wonder if it is possible to get the user and password for a PostGIS database if they are stored in the PostGis connection information. I get the connection information at the moment from the ...
1
vote
1answer
787 views

Having trouble connecting QGIS with postgres database with postgis extension

I am working on Ubuntu Precise with postgresql version 9.3 and postgis 2.0. After initially starting my postgres database and eventually getting permission errors that would prevent postgres from ...
2
votes
1answer
31 views

Joining lines by X,Y AND Z coordinates

My task is to generate 3D polygons from line data, which will then be imported into TerraExplorer 3D presentation software. Problems arise when there are overlapping lines in 2D space, but which have ...
2
votes
2answers
31 views

How to move features from one layer to another?

I have a polygon which belongs to a layer and I need to move it to another one. Is there a way to do it without drawing it again? Thanks! Dani
1
vote
2answers
44 views

Is there a way of auto_increment for the ID column

I'm creating a fictive map and so I need to create polygon after polygon. Later on I export my data as geojson. But before that I aways have to go and give every polygon a unique ID. I don't need a ...
3
votes
1answer
55 views

How to always disable the “add saved file to map” checkbox in Save as …?

I often use the "Save as.." dialog and just want the exported geojson file there. But he always enables the checkbox "add saved file to map". I really dislike it that way and it does not make any ...
4
votes
3answers
3k views

How to convert the file with projections in meters to Lat-Long in QGIS ar Erdas Imagine?

I have file in Lambert Conformal conic format for the data of Australia, Its coordinates are in meters. I want to convert it to Latitude-Longitude format. Which Projection, Spheroid and Datum I should ...
0
votes
0answers
18 views

QGIS Convert SHP to KML keep all attributes [duplicate]

I am trying to convert a SHP to KML in QGIS and want to keep all the attribute fields. As far as I can tell when you do this operation, you can only choose 2 fields (DescriptionField and NameField). ...
1
vote
0answers
25 views

Using processing using other output (result from another algorithm) as input

I have a problem. I am developing a standalone app in python and I need to use processing algorithms. I was able to use one algorithm without erros but I need to run other processing algorithm which ...
4
votes
1answer
38 views

Shapefile layers in QGIS don't display unless I zoom out

I have two shapefile layers in a Qgis project that have problems with zooming. One is a line I copied/pasted in a new layer from a set of height contours and the other one is a polygon layer I created ...
3
votes
0answers
12 views

QGIS 2.6.1 Complex polygon not displayed properly

I append two images of the same shape file which contains a single polygon with several "lakes". In SAGA it displays correctly with all the lakes as transparent but in QGIS the larger lakes contain ...
2
votes
1answer
19 views

QGIS print composer export excludes one layer

I am trying to export a map from QGIS print composer but the resulting files (I've tried all image, .svg, and .pdf formats) do not appear as the map did in the composer. It is as if one of the raster ...
1
vote
2answers
19 views

Imported TIF has dark gray background instead of white

using QGIS 2.6 I import a TIF file, and expect the import to show an image that has black lines on a white background (with some other colors here and there), as the native windows viewer will see a ...
2
votes
1answer
30 views

QGIS toolbars source code

I can see the source code of the core QGIS plugins from the repository in github. But is there any repository of source codes for QGIS toolbars also?
1
vote
1answer
17 views

QGIS Custom Symbols Group File Location

I am curious as to the location of the symbols group files. I have created numerous custom symbols, as well as symbol groups. I would like to share these with the people I work with. Thank you!
0
votes
1answer
313 views

qgis-web-client stuck on Loading Map

I'm trying to publish a map created in qgis desktop via qgis-web-client. The left hand bar loads with the layers I would expect visible but I never actually see any mapping data just a grey screen ...
2
votes
1answer
31 views

Object Inspector Button not enabled in python console of qgis

I am using QGIS2.6 version. I loaded an existing py file in a editor. Though I added a codes in the editor, the object inspector button was not enabled. Please help me in figuring out what would be ...
4
votes
1answer
132 views

Is there an issue with Zonal Statistics calculating wrong mean values?

I tried to solve the following issue by myself but without success. On the one hand I have a raster file which is the result of the processing "shapes to grid" tool. On the other hand I have a ...