Quantum GIS is a user-friendly, cross-platform GIS application licensed under the GNU General Public License.
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7 views
How to Join Attributes by Location in QGIS 1.8.0
I have a points layer with site attributes and a polygon layer with region attributes. I'd like to join the names of the regions to the point site locations using QGIS 1.8.0., on Windows XP. ...
0
votes
0answers
33 views
Python to get ids from shp dont return all records
I have some Python code to get the ids and georeference from a shapefile:
canvas = qgis.utils.iface.mapCanvas()
allLayers = canvas.layers()
nos = QgsFeature()
for i in allLayers:
if ...
5
votes
1answer
58 views
How to automatically reduce polygon size?
I am working with two polygon layers (counties & states) which I will 'intersect' to find which counties are within which states.
Due to data inaccuracies I have to change all county polygons and ...
0
votes
1answer
59 views
How to convert geometry of SHP to decimals
I try to create a line with two points. These points are obtained in a SHP layer.
How can i convert that points to decimals?
Thank you
1
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0answers
38 views
How to clip roads to exclude those within a flood zone?
I have OSM road network data in QGIS along with a shapefile showing the possible extent of a flood.
My question is: is it possible to exclude all of the roads that are in the flood zone (so as to ...
1
vote
0answers
24 views
Calculating distance and/or time taken to travel from population centre to nearest hospital in QGIS
I'm trying to find out how long it would take to travel by car from each of the Lower Layer Super Output Areas (LSOA) in Norfolk, England to the nearest Hospital (or just what the distance is and I ...
0
votes
0answers
24 views
QGIS Plugin Development - Displaying Data from a feature
I want to display data based on the feature currently selected/clicked on.
I am following a tutorial from http://www.qgisworkshop.org/html/workshop/plugins_tutorial.html.
It initially shows you how ...
0
votes
1answer
20 views
How to use expression in QgsVectorlayer label by using python?
how to show the two field values as a label on features. I have done it for a field called "ErrorDescr" with this i need to show another field values. Other field is "MarkerId"
...
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0answers
23 views
trace a transmission line for a certain distance
I’m looking for a way to easily trace a transmission line for a certain distance.
Here is the scenario that I am working with. We have an issue with our transmission line; our OMS tells us that there ...
-1
votes
1answer
44 views
How to change windows can't find D:\Program [closed]
Today, I setup QGIS. When I run msys, it appear 'windows can't find D:\Program'. Why? Thank you!
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0answers
21 views
Looks like a ghost polygon. Border line can not be deleted though two feature is the same layer
I'm a QGIS 1.8.0 user.
I received broken shape file.
I found one feature which has a border line within polygon.
I tried to delete line with tool;Merger, Dissolve, Node tool and etc.
I got the ...
1
vote
1answer
37 views
looking for datum to georeference maps of 19th century Maine
I am trying to georeference 3 (1840, 1844, and 1877) northern Maine maps. I really am not able to find which datum to use. Can anyone point me to a list of historic and regional datums?
thanks
1
vote
1answer
26 views
Easy Custom Labeling plugin does allow to save?
I use the Easy Custom Labeling plugin chose positions of the labels and safe the layer and project for continuing later. When opening again the project, the layer opens but without any objects inside. ...
0
votes
1answer
20 views
How to select behind feature which is overlapped with the same layer on QGIS 1.8.0
My issue: I received data which was created without "Avoid intersection of new polygon". There a few overlapped feature with the same layer. I could fine overlapped feature by the spatial query. But ...
0
votes
1answer
43 views
How to find the watershed area for each point in the river network？
As title, I want to find the watershed area, but using QGIS.
I have following files to work with：
stream network shapefile(polyline)
point shapefile clipped from the polyline shapefile
I want to ...
0
votes
1answer
55 views
QGIS coordinates are very large
I've created a custom map in QGIS, with a few shapefiles. I'm using leaflet.js to render the map and the shapefile points and everything lines up correctly. The CRS is set to 4326.
When I export the ...
0
votes
0answers
14 views
Loading raster from PostGIS DB into QGIS: succeeded yesterday, fails now
I have a PostgreSQL(v.9.2)/Postgis(v.2.0.3) database which includes raster layers (added through raster2pgsql).
To open them in QGIS (v.1.8.0-Lisboa), the "Add Postgis layer" menu will not work; ...
1
vote
2answers
43 views
How to select two points on a map using QGIS?
I need to select two points on a map in QGIS. I selected the element selection tool in menu view and I want to select two points. How can I accomplish this? Are there other tools or methods to ...
0
votes
1answer
27 views
QGIS Python - Convert geometry from Postgres to QgsPoint()
I have made a query in Postgres to get some points to use with python.
This points are in geometry data. How can I convert that geometry in decimals to use QgsPoint() in python?
Thank you
0
votes
0answers
18 views
Adding a WMS - connection timed out?
I am trying to add a WMS service to qgis but am having some problems. After adding the url and name of the service and clicking on connect, I am receiving the following error message:-
"Could not ...
0
votes
0answers
24 views
Nearest neighbor analysis not showing results
I'm trying to do a nearest neighbour analysis on fish shoals distribution.
I go to Vector > Analysis Tools > Nearest neighbour analysis. I choose the appropriate layer and when I hit ok the black ...
0
votes
1answer
35 views
How to find the overlap of three polygons?
I have three polygon areas showing different land types and I want to create a new layer based on where the three layers overlap each other. I thought this was a subtraction query but havent been able ...
1
vote
1answer
23 views
Why does the Zonal Statistics tool always return 0?
I have a slope raster created from a DEM raster with the DEM Analysis tool.
Now, I would like to calculate the average slope in a given area represented by a vector polygon layer.
I thought I could ...
1
vote
0answers
21 views
travel survey multi stop routing problem
I have a travel diary survey dataset that I am attempting to transform into more useful information. Currently, the data comes in the format of:
Survey# , PlaceVisited#, TravelMode, TripPurpose, ...
1
vote
0answers
73 views
Handling “bad layers” in QGIS version 1.9
I'm having a problem every time I try and open any project in qgis 1.9. It will load part of a few layers and then a yellow bar comes up across the top of the map area that says "Handle Bad layers: 23 ...
1
vote
1answer
24 views
Why are layers imported into a DB with Spatialite-Gui locked from editing?
I have a Spatialite DB which I have imported some shp files too using Spatialite-Gui.
I have full read-write access to these layers via the Spatialite-Gui, however when I open these layers from QGIS I ...
1
vote
1answer
53 views
How to create a Winkel-Tripel map of countries with different colors?
I need a good quality rasterized world map, Winkel-Tripel projection, in which all countries have different (random?) colors. No borders, text, grid or anything else on the map.
Is GIS the right way ...
-1
votes
0answers
28 views
problem with the upgrading of qgis and Lubuntu
I upgraded to Lubuntu 13.04 and to Qgis 1.9.
When I try to run the software I get this error message:
/usr/bin/qgis.bin: error while loading shared libraries: libgdal1.7.0.so.1: cannot open shared ...
0
votes
1answer
42 views
How to write an Advanced Query which gets the same results as the simple query option
Working with my data set on Late Woodland Village reanalysis in QGIS, the previous question was somewhat answered by defining the issue as a many to one. As a work-around, I summarized the info into ...
1
vote
1answer
63 views
Can I open a form in layer action?
I want to open a form (made in QTDesign) in the layer action. It is possible?
2
votes
3answers
51 views
How to preserve text when converting from .dxf to .shp?
I have tried using dxf2shp converter in QGIS but the text in dxf file is being lost during the conversion process, despite selecting export text labels.
I would be grateful if someone can help me ...
1
vote
0answers
25 views
Having trouble with Webserver configuration on Windows
im currently working on a WMS with QGIS 1.8.0 Desktop with apache from xampp. What I want to do is to have my .qgs file displayed on my webpage as a OpenLayer. So I followed this tutorial:
...
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0answers
27 views
How to hide annotation in QGIS in a organized way?
I don't understand how to hide (text) annotation in QGIS. I know I can do it simply with control+T but because many annotations are related with a specific layer I would like to organize them in a ...
0
votes
0answers
15 views
Calculating Centroid of add shaped polygons [duplicate]
I need to calculate the centroid so that it is still contained in the related polygon. I have used the centroid tool in ftools and the centroid maker and have the same results as shown below.
Is ...
0
votes
0answers
17 views
QGis non blocking notifications with pyqgis [duplicate]
I'm searching for the way to use the new QGis non blocking notification system with the QGis python wrapper. I found informations on this fonctionnality but nothing on how to use this especially with ...
0
votes
0answers
42 views
plugins available via WMS?
I have QGIS server up and running and all is well, and I want to create a plugin in PyQGIS. But I need the plugin to be available to the users of the web maps in which my server serves. So is it ...
3
votes
2answers
77 views
Can the new Mapbox Vector Tiles be used as a QGIS basemap?
With the implementation of the mapbox vector tiles begs the question of how these could be used as a basemap in a QGIS printed map (assuming anyone cares about printed maps anymore!).
To use OSM data ...
4
votes
1answer
47 views
Splitting polylines according to coincident points with other polylines?
I'm looking for a method or python script to split polylines according to coincident points with other polylines, but avoid splitting the ones which just intersect (without a sharing point like the ...
1
vote
1answer
28 views
QGIS Field Calculation convert to ArcGIS
I have a field calculator expression I use in QGIS to generate unique IDs that are sequential, but start with a text string. I now need to perform the same thing in ArcGIS, but I am unsure of how to ...
1
vote
0answers
19 views
QGis Grid statistics for polygons error - Module caused access violation!
I'm trying to calculate statistics for a raster layer using an overlaying polygon layer, I'm using SAGA "Grid Statistics for polygons" function, but it returns an error, sadly.. So in the sextante log ...
0
votes
0answers
24 views
Spatialite, to speed performance, when should I create Views, Indexes or additional spatial tables?
I’ve got a large Spatialite database with a table of lines (roads, rail and water). I created a spatial index of the geometry to speed things up.
This works amazingly well when I’m zoomed in ...
4
votes
1answer
54 views
Raster to vector with gaps in Landsat ETM
I need to find size of water area from a raster (jpg) using QGIS 1.8.0-Lisboa. The raster is a Landsat image with gaps of data in it.
I used Polygonize, but the output file shows wrong polygon size ...
2
votes
1answer
29 views
Is there an address gazetteer for QGIS?
I have a SQL database that has our local address database on it - it has no geometry within it, just a list of addresses and X and Y co-ordinates. I want to use this data to enable people to search ...
0
votes
0answers
6 views
Cut lines on each node and give them new start/end points for using shortest path tool accurate [duplicate]
I have to shapefile layers for a city. First contains the road network as lines the other one has point features for the nodes. Unfortunatley the single lines don't stop at each node, they often cross ...
0
votes
0answers
39 views
Export ArcGIS 9.3 .lyr symbology styles to QGIS
There are numerous posts on GIS.SE on exporting ArcGIS 10.x symbology to SLD then to QGIS; however, I don't think this is possible for ArcGIS 9.3.x.
Is it possible to convert *.lyr styles from ArcGIS ...
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0answers
25 views
Convex Hull issue in QGIS 1.8
When creating convex hulls based on input field in qgis 1.8, there seems to be always one less convex hull created for the unique values in the input field.
For example;
I have a point vector file, ...
0
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0answers
24 views
qgis webclient displays only one layer
I installed qgis webclient. The helloworld example works fine. I tried to use an own qgs-Project for presenting with qgis webclient. However, only one layer is display in the web browser.
With ...
0
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0answers
34 views
Difficulty installing Quantum GIS on Linux CentOS 6
I followed the instructions given by R.K. in this question:
How to install QGIS on Centos 6?
by typing this command:
yum search qgis
I received this reply:
Loaded plugins: fastestmirror, ...
3
votes
1answer
46 views
How to delete points from CSV point layer?
I have a point layer produced from importing a Delimited Text Layer and I would like to delete some points. It seems that it is not possible to toggle editing in a point layer. How can I delete the ...
1
vote
1answer
45 views
Extraction of contour lines starting from 0 elevation
I need your help regarding extraction of contour lines in QGIS. I am new to QGIS (in GIS actually).
I followed the tutorials on extracting contour lines from DEM (which I downloaded from cgiar.srtm) ...
