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

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2
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3answers
2k views

Is there a way to clip the Google Satellite Layer from open layers plugin?

I have imported the Google satellite imagery though open layers plugin. I would like to clip it to a polygon shapefile of New York State. Is it possible to do this? I tired the GDAL Tools and it wont ...
1
vote
1answer
329 views

Problem in libtiff.dll when starting QGIS

When I try to start QGIS 1.8.0 I get the error message "Can't find procedure start address TIFFMergerFieldInfo in libtiff.dll" and the program won't start. I have downloaded and reinstalled QGIS ...
0
votes
2answers
84 views

How to align directions of connected lines?

I have a vector line made of different pieces of lines with different directions. I merged the lines to one. But this merged line still have different direction in its "invisible" parts. I want to ...
0
votes
0answers
142 views

Download/Upload GPS/Qgis don't work anymore

We were using Qgis and GpsBabel to download waypoints and tracks from GPS garmin 60 or 76. Since few weeks, this is not working anymore. There is a error windows, and nothing is created. I tried ...
0
votes
1answer
164 views

Cadtools getting the distance in meters

While doing the parallel line method by using the cadtools its asking the distance in meters but i need the parallel in feet values(I need to enter the distance in feet values). currently we are using ...
3
votes
1answer
713 views

How to uninstall standalone QGIS & reinstall in OSgeo4w on Win7?

I need to apply a patch to QGis but installed as standalone instead of OSGeo4w: foolish. I'd like to uninstall then reinstall via OSGeo4w so as to have linux-like updating support, but before I do ...
1
vote
2answers
131 views

How to acces features attributes when creating renderer?

I'm trying to customize the rendering of a point layer in QGIS using python. Thus I have written a renderer class as explained in the documentation ...
1
vote
2answers
112 views

False easting/westing with MGI/Austria M28

After extracting the XY coordinates from geometry data via "save as csv" I get coordinates which are about 150 km more in the west than they should be. North/south seems right. I set the CRS to ...
4
votes
1answer
795 views

How to deploy a QGIS Python Standalone Application with minimum installation size?

I am trying to create a Standalone QGis Application using python. I was able to create the nice looking shapeviewer application by following the steps here. Now I would like to deploy this in ...
3
votes
1answer
761 views

Split vector layer by field name

I have a vector layer of 108374 lines I want to split the vector layer into field names of the layer, which is 17. Now, I want to create a new vector layer containing one of the field names e.g. ...
3
votes
1answer
163 views

draw lines with an angle inside a rectangle in python

I am trying to make a plugin for Qgis with python. I have the four corner coordinates for a rectangle. I want to give the user the inputs, line space and angle (0 -180 degrees). With these inputs, I ...
3
votes
1answer
594 views

How to set up QGIS print composer options from the python console?

If I have a print composer called "ABC", I would like to "tell" its composer that I would like to update "Map 0" to simulate the "set to map canvas extent" button activation update certain text ...
1
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0answers
106 views

Couldn't load SIP module - python disabled

Recently my QGIS started refusing to load SIP module, from day to day without any significant changes in the system (I'm on Windows7 x64). Message thrown at startup: Nie można wczytać modułu SIP. ...
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0answers
67 views

How to populate polygon extents to an attribute table in QGIS

Is there a way to calculate the XMIN, YMIN, XMAX and YMAX of a polygon and write it to a field in an attribute table? The Geometry functions available in the Field Calculator are for points. ...
1
vote
1answer
185 views

How to center the labels in QGis?

I have a shapefile containing some US sections from the Public Land Survey System. I would like to display the labels in the middle of the sections. I found the "Placement" option in the "Label" ...
2
votes
1answer
165 views

selectedFeatureCount vs featureCount?

I do from qgis.core import * layer = QgsVectorLayer(r"D:\file.shp", "boundingBoxes", "ogr") layer.featureCount() outcome is 428 layer.select(layer.pendingAllAttributesList()) ...
1
vote
2answers
55 views

In Quantum GIS, how do I specify the units for a shapefile?

I'm trying to create a shapefile of fields, drawing polygons around each field, and having the acreage calculated in the attribute table. I believe I have the projections correct. It's not coming up ...
2
votes
1answer
115 views

CRS Austrian Lambert/WGS84

I am totally new to Qgis (or GIS in total): My problem is to get two layers in same CRS to do an intersection and further analysis described in the blog of underdark (Groupstat tutorial). My is the ...
7
votes
1answer
189 views

How to access and/or manipulate table data in QGIS composer label?

When setting up a map to print using the QGIS Composer, how can I insert a label linked to a specific table record? I have been using the latest development build (1.9.0) which has the new Expression ...
1
vote
1answer
1k views

Can QGIS (1.8.0 Mac) rotate the entire view of a project?

Can QGIS (1.8.0 Mac) rotate the entire view of a project? that is, have north pointing in a direction other than up on the screen and on output? of course, while still allowing adding new layers etc.
1
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0answers
137 views

How to apply new WFS-Filter features like intersect

I was pleasantly surprised to find very much enlarged filter support in QGIS-Dev (1.9.0_Master). One application would be a WFS-Filter which combines $geometry and Intersect in order to load only the ...
0
votes
1answer
533 views

How to read the attribute values using pyQgis?

What is the way to get the information contained in the attribute table, say in column 2, row 2 using pyQgis?
4
votes
1answer
321 views

What functionality exists to calculate Cut and Fill for excavation?

Does qgis have the ability to compare and quantify existing versus proposed elevations?
3
votes
3answers
112 views

How to match air photo to existing vector layers on Mac OS?

I'm trying to add an air photo to a project and match it to existing data. CanVec data is mostly based on the old CIA dataset of the 60's and is hopelessly out of date, but the roads are up to date - ...
4
votes
1answer
185 views

Can county level info be brought into a map?

I have a csv file of Clovis projectile points that were recorded only with the county in which they were found, no coordinates at all, no shapefiles. Is there a way to bring these into a state map ...
4
votes
2answers
475 views

QGIS, Postgis: Is it possible to create a new postgis layer?

Situation: I have a postgis vector lay that has lots of line segments (the features). I want to create a set of new layers each of which contains a subset of the features of the original layer and ...
2
votes
1answer
62 views

QGIS: Making changes to vector layers stored in PostGIS

I have a vector layer stored in PostGIS. I split several lines in the layer and simplified others by removing vertices. When I tried to save the changes to the layer I got postgres more postgres ...
11
votes
2answers
1k views

How to create contiguous area cartograms in QGIS or R?

Here is what I want to achieve (on the right): I am looking for a tool or a method to transform a shapefile (with QGIS or R) into this form. And please be aware: It's not just clipping a hexagonal ...
0
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0answers
254 views

How to use raw_input() in QGIS python console?

I'm hoping to use raw_input() inside a loop to prompt the user when s/he wants to continue running the script. However, I'm getting an error: Traceback (most recent call last): File ...
2
votes
2answers
317 views

Create polygon of buildings from Quickbird images in QGIS

I have Quickbird/Ikonos/GeoEye image and want to extract all the buildings from the image as an independent layer in QGIS. How can i achieve that?
1
vote
2answers
229 views

Having problems creating VRT in QGIS from png files

This is similar to a question asked by someone else, re OS tiles, however, there is a difference! I am a bit of a amateur in GIS and python, but if I take it slow I can usually just about work it out! ...
4
votes
2answers
479 views

Field Calculator decimal places - how can I limit them?

I've added a new column to an attribute table and performed an operation with the field calculator to populate the new column. The result is a column with a percentage. My problem isn't major but I ...
1
vote
2answers
386 views

styles for QGIS

Could someone point me to a source of line and point styles for QGIS (*.qml) - railways and transmission lines are the first two I've run up against, but I know there will be more.
1
vote
1answer
282 views

Rpy2 Unable to Load in Fresh QGIS Install

after installing qgis the a message given below is shown Unable to load the plugin: Unable to load required package rpy2. Please ensure that both R, and the corresponding version of Rpy2 are ...
2
votes
0answers
162 views

QGIS not rendering WMS layers

I'm a bit of newb' at GIS so be gentle with me. In Qgis I've set up a wms for the British Geological Survey: http://maps.bgs.ac.uk/ArcGIS/services/BGS_Detailed_Geology/MapServer/WMSServer? Now ...
4
votes
1answer
272 views

Personal shell launcher for PyQGIS

I have changed a shell launcher found at http://inasafe.linfiniti.com/html/id/developer-docs/platform_windows.html as to fit my wish: setting the system environment variables to be able to use PyQGIS ...
2
votes
0answers
215 views

WMS and Quantum GIS/ArcGIS

I periodically use a nice basemap served by the Utah state government in QGIS. Recently they upgraded their server from ArcGIS Server 9.3 to ArcGIS Server 10.1. Ever since then, I can't seem to get ...
1
vote
1answer
132 views

Can not import qgis.core in python

I installed OSGeo4W. I have no other Python version on my computer. I can import osgeo. But when I try to import qgis.core I am getting the error: >>> import qgis.core Traceback (most ...
6
votes
1answer
416 views

ISIS to GDAL to QGIS: Georeferencing Mars Images

I'm trying to use QGIS to view some images from the Mars Reconnaissance Orbiter Context Camera. I use ISIS3 to download the images and convert them to mapped .cub files, following the instructions ...
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0answers
58 views

How to delete a point with known coordinates in python?

I was wondering if there is a piece of code that does the opposite that setGeometry does and removes a point if there is one at x and y coordinates?
4
votes
3answers
666 views

Can OpenLayers layers in QGIS have transparency?

I often would like to set the basemap back by lowering the transparency. I would love to have this option in QGIS for OpenLayers layers, such as the stamen layers, google, etc. Is this possible? I ...
0
votes
0answers
139 views

How do I stop polygons from a .kml layer disappearing as I zoom in on the layer?

I am relatively new to GIS stuff and have a query about .kml files in QGIS. I have downloaded the .kml filefrom ...
1
vote
1answer
129 views

Modify 'Codepoint with Polygons' to add new fields

Sorry if this is a simple question - I'm just beginning in QGIS. I'm using OS Codepoint With Polygons data set which provides shape files of each Postcode area within the UK. Within each postcode ...
4
votes
1answer
322 views

How to measure the distance of multiple points to a line

I have two shapfile in QGIS to which I am trying to find the distances between. I have a shoreline which is a vector line and then I have hundreds of data points in the ocean. What I am trying to find ...
2
votes
0answers
304 views

Transform RGB-Map to CMYK (qgis, opensource tools)

I want to print a map I made with qgis. For the print I need CMYK-colors but the print-composers pdf-output is RGB. How can I convert the RGB-map/-pdf to CMYK?
1
vote
1answer
139 views

How to run “create mask” from the console?

There's a plugin called "create mask" for qGIS and trying out some simple scripting from the Python console. I would like to call it after I select the vector features I want, then do more related ...
6
votes
1answer
77 views

Is there a way to select only a certain polygon for editing?

I have a spatialite data base with 4300 polygons contained within. I wish to be able to edit the polygons but once i have highlighted the Polygon from the attributes table i find it hard to edit the ...
1
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0answers
58 views

Avoid rounding of coordinates in pyQgis

If I get the coordinates of a polygon in qgis by x = geom.asPolygon() It rounds off the coordinate from i.e. -27,200,334.86 to -2.72003e+07 How can I avoid that?
0
votes
2answers
147 views

loading CanVec directory full of .shp files

I'm totally new to QGIS, and trying to view a Canadian Topo map as published on an iMac - I don't want to change it. ...
1
vote
1answer
81 views

How do you Select an existing vector Layer and Edit it, using python?

I'm developing a small plugin that needs to be able to select a vector layer programatically based on what layer the user has selected. However I'm not sure how to do so. I believe I found the two ...