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

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23 views

QGIS Select by Expression

A basic QGIS 2.2.0-Valmiera, Select By Expression - Field Calculator question. Introduction I am a geologist searching through a geological database (see attached figure). I have a shape file and ...
-5
votes
0answers
16 views

How to add button in google maps where i have polygon? [on hold]

we are plotting polygon on google map using script.I want to add one button where my polygon plots. Using Front end as .net we are plotting polygons in google map.We need to add one clcked button on ...
3
votes
2answers
127 views

How to show just some labels based on feature intersection of layers?

I'm trying to use "expression based" labeling in Qgis, but I'm stuck with a particular case. I managed to use it for a project with the help of other topics and FAQ but I'm not enough skilled to ...
3
votes
1answer
93 views

Is it possible to label bar charts?

I have added bar charts to my map and this works fine. But I have no idea how to add values to the bar chart. For example one bar shows the value of 2000 and another shows the value of 2100. Is it ...
0
votes
1answer
68 views

How do you install updates/patches for bug fixes in QGIS?

I'm trying to fix this bug in Qgis 2.0. I suppose the code, under the "Files Changed' tab needs to be copied/installed somewhere? Could you please advise on how to do so? I cannot find any help ...
3
votes
1answer
48 views

Unable to get python-qgis-common on Kubuntu 14.04

just upgraded my Kubuntu from 13.10 to 14.04 LTS and lost all plugins. Found out that "python-qgis-common" is not installed. Tried to install it but was told that it depends on "sip-api-10.1" which ...
0
votes
1answer
70 views

QGIS 2.0 Howto copy raster data from a QgsRasterDataProvider to an OpenCV matrix

I'm hacking the half day arround a problem and that I' thought it was simple one. I'm using C++ (QtCreator) QGIS 2.0 und openCV2 on an 64 bit Workstation runnig Debian Wheezy. The Application I try to ...
0
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2answers
78 views

How can I see average of raster value over certain area, marked by mouse?

I have a raster in Quantum GIS and I am just exploring it. How can I see average of raster value over certain area, marked by mouse? In other words: How can I select particular area in QGIS? How can ...
1
vote
2answers
220 views

Creating a Clickable Map with OpenLayers?

My girlfriend is trying to create a webmap using OpenLayers that is similar to this one, which was done in ArcGIS Server. I thought I'd be able to help her as I have GIS and some coding experience but ...
2
votes
1answer
100 views

How to load a memory layer into map canvas an zoom to it with pyQGIS?

I would like to load a vector memory layer into the map canvas with pyQGIS. Background is, I create a memory buffer layer around point data. While iterating the points I would like to visualize the ...
1
vote
1answer
87 views

QGIS crash Ubuntu 14.04

Encountering a crash when requesting QGIS 2.2 to access data on desktop machine. Running Ubuntu 14.04 LTS. $ qgis Warning: loading of qt translation failed [/usr/share/qt4/translations/qt_en_AU] ...
1
vote
1answer
24 views

Split a line feature using nearby points

I have a line shapefile and a point shapefile, and the line has its own segments and its attribute table, the point shapefile has points near the line above, not on it and the close ...
32
votes
4answers
6k views

How to migrate from ArcGIS for Desktop to QGIS?

Our lab has about 10 projects in ArcGIS 9 (a couple are made in ArcGIS 10) that includes the following in each: A georeferenced (WGS1984 geographical projection) raster seafloor image, representing ...
7
votes
3answers
464 views

How to use ZonalStats plugin?

I am using QGIS 1.8.0 on a Windows Home Premium 7 machine. I have a single band TIFF that is 187 MB in size. My vector polygon shapefile represents a regular grid of a 147x112 36kmx36km grid cells. ...
0
votes
1answer
38 views

Excel Nad83 table to gpx-Total noob

I have some waypoint locations that I have entered into a spread sheet in Nad83 the format of table looks like this NAME, -, -, UTM ZONE, Easting, Northing, -, Comment 1184236, 1, CP, 15, 451596, ...
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votes
3answers
77 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 ...
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votes
0answers
24 views

joining polylines on geometry and attribute

I have dowloaded an Open street Map shapefile containing streets and their attributes, for my whole country. I have qgis and spatialite_gui and a very basic understanding of SQL The problem I have is ...
0
votes
1answer
72 views

Add custom CRS - 2.2.0 Valmiera

i've builded a custom proj.4 library, tested it by command line (proj and cs2cs) and with postgres/postgis. All works fine. Now i'm trying to make the same with Qgis 2.2.0. I've replaced the original ...
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votes
0answers
11 views

QGIS 2.2 Changeing txt data in theme table not working

A week ago I upgrade from QGIS 2.0.1 to 2.2 and try to edit some simple point themes I made recently. To my surprise, QGIS 2.2 randomly - not allways, does not allow me to change text I type into text ...
0
votes
1answer
21 views

QGIS 2.2: GDAL Grid (Interpolation) Error

As much as i understand Raster -> Analysis -> Raster (Interpolation) can provide me with a terrain file out of a shape file with a Z coordinate. I select the input and output file and a Z field. It ...
0
votes
0answers
10 views

Split/Erase/Differentiate polygon by polygon within a same layer

Is it possible to split a polygon with a polygon within the same layer in QGIS ? As in the image, i want the Polygon 2 to be split & the pointed area has to be retained as a separate polygon. ...
0
votes
1answer
12 views

Building with MinGW 4.8

I'm working on a project where we would like to add QGIS features to an existing Qt application. The Qt application has been built with Qt5.2.1 using MinGW 4.8 and thus I think I need to build QGIS ...
0
votes
1answer
25 views

Changing band for greyscale in plugin

I am trying to make a qgis plugin to change which band in a multiband data set (netCDF where the band represents time steps) is used for a grey scale rendering. The file works fine with manual ...
45
votes
4answers
16k views

How to build effective heat-maps?

Using ArcGIS, QuantumGIS, Grass, and/or GVSIG What are some of the tools and processes involved in building effective heat maps? What are the plugins involved? What are the major data requirements? ...
1
vote
1answer
81 views

How to go with…somewhat complex geological maps in QGIS?

Just a follow-up to this question QGIS: Line to polygon conversion. Not sure do i have to continue there itself... We are currently digitizing a geological map...which has 36 features in total. Some ...
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0answers
29 views

back up of qgis file

Can we recover a previously saved version of qgis file? For example: I have saved my qgis file about an hour but I need the yesterday's back up of qgis file. The file which does contain today's saved ...
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0answers
32 views
+50

How to translate .bil files in a batch mode with QGIS?

I have some .bil files that I would like to convert into ASCII Gridded XYZ format files. It seems to work well with the Raster>Translate tool of QGIS when I process one file at a time. But I would ...
0
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0answers
17 views

How do I use QGIS 2.2 to plot some locations on a map (of the US by zip code)?

I am a newbie to QGIS. I just installed it on my MAC Airbook with Mavericks. How in the bloody heck do I simply plot a few locations on a map of the US? All of the tutorials I can find on the web ...
1
vote
1answer
22 views

Including two different maps in one QGIS Print Composer

How do I use print composer in QGIS 2.0.1 to produce a final product with two different maps on the same sheet? I can't figure out how to use the 'add a map' button to add anything other than a ...
1
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0answers
27 views

Converting QGIS Labels to a Polygon Shapefile

I am trying to create an annotation feature from labels and then export this out as a polygon shapefile (the resulting shapefile can then be loaded into ArcGIS online to basically have labels without ...
1
vote
0answers
36 views

How to get Drainage Divide and Streams from DTM

Does anyone know how you can get a map like this attached, having the digital terrain model? I'm sorry, but I do not know what is the exact technical term in English for them. I hope you understand ...
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vote
4answers
360 views

Needed shape file for Australia and New zealand

I was trying to find a shape file which has Australia and New zealand together(states) so that i could convert to jvectormap for ANZ. where i can find it?
1
vote
1answer
83 views

how to rename the band-names of a layer stack?

I created a layer stack of 20 images (all GTiff-files) using the gdal_merge tool in QGIS, available at: raster > miscellaneous > merge The result is a GTiff layer stack of the 20 images, but ...
0
votes
0answers
19 views

MODIS images set CRS and reproject

I am developing a plugin which reads MODIS images, and I know that MODIS images are in sinusoidal projection and I need to set that CRS and project the image to WGS84 (epsg 4326) in python. I search ...
0
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0answers
27 views

Why do the SHP lines in QGIS Android look jagged (very simplified)?

I use QGIS for more than five years. I'm trying to make my way with QGIS Android for a while now. For some time I experience the following problem with the "nightly build" 2.0.1-Dufour: the SHP lines ...
0
votes
0answers
12 views

QGIS: Clipping a line layer using a polygon and getting an empty shapefile

I am using QGIS 2.2.0 and want to clip a line layer (roads) so that only those inside a polygon are shown. When I do this using Vector->Geoprocessing Tools->Clip I only get an empty shapefile as an ...
0
votes
1answer
16 views

QGIS 2.2 - expression string builder to ignore NULL values

Simply put, I would like to create a rule-based filter whereby you add 2 columns together and you get a certain colour as a result. However, some fields in Column_1 may be NULL and those exact same ...
5
votes
1answer
256 views

How to avoid duplicate GIDs when copying features from one PostGIS layer to another?

When I enter new elements (features) in another Postgres layer, I can do it in two ways: Drawing new element(s) (with 'Add feature') which I do rarely or Copying (or cutting) some elements from ...
2
votes
0answers
17 views

Programmatically change layer position in the table of contents (QGIS)

I am trying move/position a layer to the bottom of the TOC by using addTopLevelItem on all other layers. I unsure how to reference the layers as QTreeWidgetItem's. def bg_bottom_level_item(self): ...
2
votes
2answers
29 views

loss of attribute data when copying between layers

I am trying to copy points from one layer to another in QGIS 2.2 The problem I get is that all the attribute data from the copied points is missing when copied onto the new layer, the columns show ...
1
vote
1answer
38 views

QGIS: Line to polygon conversion

Currently we are working in a geological project..in which all the Contacts, Linear & some other geological features have to be captured. The thing is most of the features have to be Captured as ...
1
vote
2answers
37 views

How to I convert from decimal degrees to meters in Qgis?

I am trying to convert from decimal degrees to meters in QGIS. I have a shape file that is currently in WGS84/UTM zone 19S. I have tried the save as - browse - WGS84 EPSG:4326 but this appears: ...
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0answers
39 views

finding orientation -direction of polygon

i have one polygon layer and another is point layer,i want to findout orientation automatically of line of polygon which is parellel to the street and closest to the point.i am using Qgis 2.0 .is it ...
0
votes
1answer
36 views

In QGIS are there similare construction tools to ArcGIS?

For a project we are using ArcGIS to reshape autogenerated features. For that we often use the construction tools polygon, rectangel, circle, etc in ArcGIS. The right angle is also an often used tool. ...
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0answers
11 views

QGIS for Android - installation with QGIS-Installer faild on Galaxy Note 10.1 LTE

I once installed QGIS for Android. After deinstallation i'm not able to reinstall QGIS on my Galaxy Note 10.1 LTE. I've enabled App installation from unknown sources! Any ideas where the problem ...
0
votes
1answer
150 views

clip one layer with the current map layers

I work in a little companie where the main goal of employees in GIS is to have a quick view of the issues on a study area. It would be very useful to have a tool wich clip all the layers of the ...
3
votes
1answer
361 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
4 views

Problems rendering tilestache served mbtiles in QGIS

I came across Geoffery Hing's walk through on using Tilestache to serve up mbtiles to QGIS. I followed the configuration and I was able to view tiles in the browser without any problems. However, when ...
0
votes
1answer
16 views

Trouble Using Selection Expression in QGIS

I am trying to use the selection expression box to highlight counties by state FIPS. When I use the OR conditional all counties across the US get highlighted. So for example, STATEFIPS = 1 will ...
0
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0answers
17 views

custom toolbar combobox: issues with adding functionality

I've added a combo box to my custom toolbar in QGIS (based on this thread QGIS - Add a combobox to a toolbar), but it doesn't populate unless I reload the plugin. def __init__(self, iface): ... ...