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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0answers
12 views

QGIS: Need to remove unwanted white bands when raster layer are overlapping

In my project when raster layers are overlapping a white band appears the edge of the top layer. How can I remove it and obtain a seamless overlapping of the raster ? (I have try to built a vrt with ...
-1
votes
2answers
41 views

How can I project a power line net in QGIS?

I am working with power lines net using the software QGIS. I would like to know which plugins or tools do I need to be able drawing (projecting) them.
0
votes
0answers
8 views

Not empty geometry having blank text

i'm having problem with geometry column, for some rows i have geometry with blank text, this query will describe more the problem : select geom, ST_AsGeoJSON(geom), ST_Isvalid(geom), ST_IsEmpty(geom) ...
0
votes
0answers
8 views

Some items have coordinates switched when loading PostGIS layers in QGIS

I am having problem with strange coordinates switching when loading PostGIS layers in QGIS. First, I thought, that problem may be cause by the use of GROUP_BY feature in layer query, but later the ...
0
votes
1answer
86 views

Import Shapefile on postgis doesn't show in QGIS

I'm currently working on a project about a database and some shapefiles. The database is built on PostGis with tables including some dots as geometry type columns. Once imported them on QGIS, I can ...
1
vote
1answer
85 views

How can I add grid lines to a print composition using pyqgis?

I'm writing a qgis plugin to create an image in the print composer of the current map. I can get the map rendered in the proper place with a frame of the right width, and I can get grid annotations ...
1
vote
3answers
339 views

How to create random point in according polygon for each dataset entry in a list (with R)

I have an area divided into polygons, and a dataset of observations which has a common field with the polygon layer. I now would like to generate a random point for each dataset entry within the ...
1
vote
0answers
10 views

Incorrect display of national characters from Spatialite in QGIS, Windows

I used this tutorial by Underdark (thanks much :-) ) to convert my area of interest from OSM file (whole Czech Republic downloaded from Geofabrik.de server). Used OSGEO4W shell (saying "GDAL 1.11.0, ...
1
vote
2answers
44 views

Relationship of QGIS to its sister programs?

I'v e been using QGIS 2.4 for a number of months now and we are using it a bit at work. I noted that when I did the initial install a number of new icons appeared on my desktop namely MSys QGIS ...
0
votes
0answers
23 views

Obtain an altimetric map from a layer with lines

I have a layer with contour line and I need a map with polygons colored depending on altitude. Something like this The three shades of brown identify slope: absent, moderate or marked. I know ...
2
votes
1answer
215 views

QGIS 2.0 - 2.4: Color Ramps Missing?

Since QGIS 2.0.1 the default color ramps and styling symbols seem to disappear for some users. For me, this started with QGIS 2.0.1 and still consists with 2.4. I can neither choose Smybols when ...
3
votes
1answer
405 views

Area overlay of census on Zip Code

I have census block data polygons. I want to overlay them over Zip Codes (larger polygons) in order to estimate the population in the Zip Codes. Or overlay buffers around toxic waste sites over census ...
0
votes
0answers
16 views

GISBASE not set [on hold]

Hi am VERY new to all this. On Windows 7 and downloaded QGIS 2.4, I'm trying to follow a tutorial on how to manipulate Lidar data and have got to the "create new mapset" but cannot finish because says ...
2
votes
1answer
226 views

How to label vector features programmatically?

I am using python for QGIS 2.0.1 and I have a vector layer of points representing the positions of state labels. I want to display the 'state abbreviation' attribute on the corresponding point for ...
1
vote
2answers
37 views

python qgis 2.4 : display a view with symbology

I have managed to display a view created using postgresql from qgis using python code: uri = QgsDataSourceURI() uri.setConnection("localhost", "5432", "stat", "postgres", "admin") ...
1
vote
1answer
24 views

Creating New Layer After Sorting Attribute Table using QGIS?

I have been self-teaching myself some open source GIS. I downloaded QGIS and have been following this four part tutorial - ...
0
votes
0answers
20 views

Lining up three Layers that use same Coordinate Reference System (CRS) in QGIS?

How do you make all borders of a layer equal? they should be equal but i don't know how, mCRS layer is all in philippine zone 5(EPSG:3125), with the same formula/equation, I'm new to QGIS and I'm ...
1
vote
1answer
82 views

What's the purpose of wms_metadata.xml and admin.sld?

I've installed QGIS Server and it works fine. But in /usr/lib/cgi-bin/ folder I've found 2 additional files - wms_metadata.xml and admin.sld. What is the purpose of these file? I've never used them.
1
vote
1answer
14 views

QGIS: how to identify a single raster layer on a big project?

I have QGIS project loaded with many raster files. For a given area I am looking to identify which (raster)layer provides the visible data. To start, I will already be happy with a manual solution. ...
1
vote
1answer
22 views

Merged Layers turned into square shape cause by single layers in QGIS?

What I did is merged the 30 layers of the map (Isabela Map Province - Philippines) and below is what happened. How do i remove the inside map of the border? I'm new to QGIS and I'm using QGIS 2.4 ...
0
votes
1answer
21 views

Can FileGDB SDK be made to support custom coordinate systems?

In May 2012, a question asked about File Geodatabase (*.gdb) support in QGIS? In the comments there it was pointed out by @MattWilkie that the FileGDB SDK does not support custom coordinate systems. ...
3
votes
1answer
145 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 ...
1
vote
0answers
21 views

PyQGIS: Editable Combobox for Value Map widget isses

I am having issues with an editable combo box in QGIS 2.4. The edit widget is set to Value Map with an uploaded CSV. However, if a new values (not included in the key value pair list) is added, the ...
2
votes
3answers
892 views

How to search feature in Qgis?

How is it possible to search feature on Qgis? I have lots of points with Id. Is is possible to search points using ID? Update: I'm looking for a solution that centers the map to that point.
9
votes
4answers
4k views

Tutorial on how to model flooding using data from gauging stations along rivers in QGIS?

Can someone please direct me to a tutorial where I can learn more about how to model flooding using data from gauging stations along rivers using QGIS?
1
vote
0answers
49 views

How do you modify selected geometry with a function in qgis python console?

My example use-case is that I want to redistribute vertices along lines as in Redistribute linestring vertices to specified distance and I've written some functions to do some of the work: import ...
0
votes
0answers
64 views

QGIS 2.4: plugin changes map tool canvas click behavior from 2.0

I had created a plugin for QGIS 2.0 to add new features more easily. It involves changing extents and updating snapping options along with triggering the default actionAddFeature(). However, I've ...
0
votes
0answers
71 views

distance difference in Google Earth with exported GPX or KML compared to source shapefile

I've converted a shapefile (points) to KML with QGIS. Points in the shapefile are within 100m distance from each other. When I measure it in Google Earth, the distance changes to 80m. The same ...
1
vote
1answer
225 views

QGIS Updating composer label text via python - problem with Item Properties panel

I am writing a plugin that replaces the text of a composer label based on its itemID. When I change the text of the label using: item.setText("Hello World") the label changes on the composer but ...
1
vote
1answer
20 views

QGIS 2.4 Attribute Table Search Bar?

I am learning how to use QGIS and am following various tutorials. My version of QGIS (2.4) does not have a "look for" search bar in the attribute table window as seen in older versions in screenshots ...
4
votes
1answer
140 views

QGIS 2.0.1 linking table issue, MSSQL 2008 database

I'm trying to link tables in QGIS 2.0.1 and MSSQL 2008 database. I can link them but when I try to open the attribute table QGIS throws an error and shuts down creating a *.dmp file. I saw that ...
3
votes
2answers
1k views

How to split a polyline into points at certain intervals?

I am trying to split a polyline into points with 2m intervals in ArcGIS but I don't have the necessary license. Is there a way that I can do this in QGIS? Context: I have drawn a hypothetical lake ...
2
votes
1answer
30 views

How to do loops on raster cells with python console in QGIS?

I'm new here and beginner with python. I'm looking for a solution to my problem for some hours but now you are my last chance... I'm using the python (2.7.5) console in QGIS (2.4.0). Is there a ...
2
votes
2answers
76 views

How to convert data from a .gdb into a shapefile without ArcMap?

I have a .gdb folder with LOCK Files, FREELIST Files, ATX Files, GDBINDEXES Files, GDBTABLE Files, GDBTABLEX Files and, SPX Files. I want to convert the parcel data within this folder into a ...
0
votes
0answers
27 views

Reading Points as PolyLines

I'm currently developing an Android app where I need to show some information on a map, which is stored as Shapefiles (.shp + .shx + .dbf). I noticed that when the shapefile is opened in QGis, a nice ...
3
votes
1answer
45 views

How to display bidirectional flows?

I'm working on a map showing oil shipping. Basically, I have a a series of nodes/line segments that make up the shipping network. I've joined the sums of oil that traveled along each node, so can ...
1
vote
1answer
20 views

How to export drivingDistance results in pgRoutingLayer on QGIS 2.2.0?

Hi and first of all congratulation for the great work on working and explaining the posGIS functions in QGIS : it makes this rich GIS enven richer. Thank's to Underdark's pgRoutingLayer extension, I ...
21
votes
3answers
3k views

What do I need to know, to develop a plugin for QGIS?

I wish to develop a simple plugin for QGIS, which will open some data, and some specific processing. I have quite a it of development experience with ESRI's Arcojects, but haven't developed with QGIS ...
1
vote
1answer
96 views

How to creat multiple rings between two circular buffers?

I am working with mathematical-ecological modeling and I am also a new user of QGIS Software. First I am creating 3 circular buffers with same center (shape center) covering a region with roads (shape ...
1
vote
0answers
25 views

Features in .shp can't be identified & won't render

Using QGIS 2.4.0 on Windows 7 Service pack 1. I have several .shp's, all polygons, that give me the following problem: 293 features are listed in the metadata and shown in the attribute table but the ...
0
votes
1answer
90 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
1answer
42 views

Not able to save edits to vector layer in QGIS

I have a vector layer with about 200 features. So far I have been able to add polygons to this layer just fine, now it is giving me trouble. When I draw the polygon and try to save edits, the polygon ...
1
vote
1answer
21 views

Merge multiple linestring features into a single multilinestring

Using QGis or ogr2ogr how do I convert a vector file containing multiple linestrings features into a single multilinestring feature? At the moment I've been doing this manually by converting the data ...
2
votes
3answers
99 views

How to highlight polygons within another polygon?

I want to symbolize public buildings in OSM data. For Example: There is a polygon and in column "amenity" it has the value "school". But i don't want to highlight this polygon, but the buildings ...
1
vote
0answers
16 views

Add a new polygon to an existing shapefile from wkt in QGIS

I have a layer of polygons in QGIS; I want to add programatically (pyqgis) a new polygon to this layer using WKT. Example: mywkt = POLYGON ((522762 376413 0,530635 368671 0,522237 353713 0,522762 ...
1
vote
0answers
37 views

Editing the QGIS Attribute Table

Is there a way to edit the name, type and length given to each column on the attribute table once the information has been imported from Excel?
4
votes
2answers
517 views

Where has the cartogram plugin for QGIS gone?

This plugin used to be downloadable from Carson Farmer's plugin repository page. However, the repository is broken. An old version of the plugin source code is still available at ...
0
votes
0answers
14 views

QGIS custom labeling by clicking on polyline (and polygon)

QGIS has now few really good options for custom labels but I can't find a way how easily manage labels along polylines. Is there any tool which helps me to place labels by clicking on polyline so the ...
0
votes
0answers
6 views

QGIS web client: “Object Identification” initially toggled on

I'm running a QGIS web client and a QGIS server. I want to modify the initial settings of the QGIS web client so that the "Object Identification" mode is toggled on from the beginning (just like ...
3
votes
1answer
62 views

Saving selection as new layer in QGIS 2.4?

I've selected a number of polygons from one layer and want to create a new layer. Because I can't right click using a mac how do I find "Save Selection As". Its not in the list in the "Layer" ...