Quantum GIS is a user-friendly, cross-platform GIS application licensed under the GNU General Public License.
0
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0answers
15 views
fill a polygon shapefile with color in qgis
I want to know how to change the color of a polygon shapefile in qgis using python console.
I have a list of values and i need to change the polygon color for each value, like a render!!
Thanks a ...
0
votes
1answer
14 views
QGIS Symbology changes by number value
I've gotten a state file with count outlines joined to an attribute file that shows numbers of items per county. ArcGIS has the ability to set the symbology to grade the results into pre-determined ...
0
votes
0answers
16 views
QGIS Attribute table joins
I spent hours getting "null" results in joining a downloaded state and county shp file to a self-created file (SCF). What I found was that the SCF had to have "EXACTLY" the same set of names/ID#'s as ...
1
vote
1answer
33 views
How to transform World data from EPSG 4326 to EPSG 3857
I have tryed different opensource tools to transform a world data shapefile from 4326 to 3857 but I always have an error. Im not sure, but is it because of Antartica?
I have tryed with GDAL and QGIS ...
1
vote
0answers
26 views
Trigger to fill attributes (data, client ip) in table for each new objects, PostGIS
In PostgreSQL/PostGIS database stores shapefiles. Client users software - QGIS. Please help me write PostgreSQL/PostGIS trigger, which for each newly added/updated feature in layer added 'time create' ...
3
votes
1answer
54 views
How to set up Python 2.7 to work in both QGIS and ArcGIS?
I have both ArcGIS 10.1 and QGIS 1.8 installed and both include Python 2.7 in slightly different setups and in different folders (c:\Python27\ArcGIS10.1\ and c:\Program Files (x86)\Quantum GIS ...
3
votes
2answers
47 views
“GIS” Mapping on Monument - Scaling
I have a Baroque tombstone for which I have to map the damage phenoma. Normally one can use a vector drawing programm but one has always two boundaries between the different polygons. Questions:
Is it ...
1
vote
0answers
23 views
Problem using grid with a vector layer
I need to establish a model of maritime pollution and I try to use the grid option to work on ocean sectors. I tried to use my grid on a vector file, .shp, with points. Each point is a maritime ...
1
vote
1answer
32 views
How to select points within a polygon from another layer?
I'm using QGIS 1.8 with a PostGIS database and I have three postgis-layer in qgis a lines layer, a points layer and a polygon layer.
What I'm trying to do is to select a polygon in the polygon layer ...
2
votes
3answers
83 views
How to convert a txt file to shp?
I've got a txt/csv file with the utm coordinates and the hights. Now I want to upload this into qgis. This is not a problem so far. The problem is to create a shapefile out of the data with an ...
0
votes
0answers
30 views
Fill up polygons with field value
I have now defined my renderer with a color map
I want to fill it with a value in the end field of my shape file's attribute table with python
how to do it??
I use QGIS 1.8.0 with python 2.7.3
1
vote
1answer
20 views
Pseudo Mercator error?
I'm mapping on QGIS, I have a vector layer and his CRS is on EPSG:4326 - WGS 84, but also I wanted to put a satellite image, so when I do it, the image use WGS 84 / Pseudo Mercator.
The problem is, ...
0
votes
0answers
12 views
In QGIS Python can you nest QgsFeatureIterators on the same layer
I'm using the QGIS Weekly 1.9.0 in order to access the getFeatures(QgsFeatureRequest) method. The script is run in the Script Runner Plugin v0.71
Can anyone tell me what's wrong with this code? The ...
-1
votes
0answers
45 views
How to assign a SQL query to a table attribute? [closed]
I have created a plugin with "plugin builder." Now I seek to connect my plugin to postgres. I have a shapefile and I try to find a script in Python that can assign a SQL query to my table attribute. ...
2
votes
1answer
52 views
How does QGIS calculate the area of a polygon?
I am working on a project that requires the calculation of the area of a polygon by two different methods. I need to know what algorithm QGIS uses to calculate the area of a polygon. I know ESRI ...
0
votes
0answers
30 views
Use QuantumGIS to bulk-import csv files
I have a large set of .csv-files containing geographic information. Every dataset consists out of 2 .csv-files! This is my folder-structure. All files in Tracks are formatted equally and all in Routes ...
1
vote
1answer
15 views
Can I use the globe plugin on a Windows OS and where can I find the plugin for QGIS?
I am trying to add my layers (health facilities and pertinent infrastructure within a region) to a 3D image of the landscape and someone recommended I use the Globe plugin. I can not find the Globe ...
3
votes
1answer
37 views
what is the minimum to install of QGIS for it to work?
This may sound like a daft question, but I'm looking to understand what the minimum parts of the install procedure I need to install to get QGIS to work (i.e. can it be installed without GRASS etc?) ...
2
votes
1answer
33 views
Why are towgs84 definitions missing on Ubuntu 12.04 compared to Windows?
Why for some of my most used CRS the 'towgs84' part of the definition of the layer spatial reference system is missing, compared to the QGIS for Windows?
EPSG 3004, 23032, 23033 when used with QGIS ...
0
votes
0answers
28 views
Qgis WPS client and PyWPS error with output data
Hi I'm running PyWPS service with some processes. Everything is working fine bud i wanted to try Qgis plugin WPS client and problems showed up.
First thing is that my process takes a while but Qgis ...
-1
votes
1answer
42 views
CSV with latitude and longitude to a spatial points with QGIS 1.8
i have a csv file with latitude and longitude of several addresses and a shape file of a region. I want to plot this points of the CSV file into the shape file. But I don't know how to transform these ...
1
vote
3answers
97 views
How to convert KML (Google Latitude) to SHP on Linux?
I downloaded a KML track from Google Latitude. The service allows to download the tracked route from the user's profile providing a link such as:
...
1
vote
1answer
27 views
How to export a .sid image as high DPI .tiff or .bmp from QGIS?
I have 2 50 cm resolution areal photographs in .sid format.
How can I export these layers as a regular image format (like tiff or bmp) which I can then open in any simple picture viewer program?
I've ...
1
vote
0answers
49 views
Can QGIS perform graphic clipping?
In ArcGIS for Desktop there is an option to graphic clip inside the data frame - this clips the feature you're viewing without actually clipping the feature into a new feature. Does Quantum GIS have ...
1
vote
2answers
58 views
Is it possible to colour areas between (vector) contours?
...without making it a DEM first?
Joshdoe seems to have done so ("Styled in QGis") here but doesn't say how.
Thanks!
1
vote
1answer
51 views
How to symbolize more than one attribute simultaneously in QGIS?
Each symbol can show different properties such as temperature and pressure, etc. I want to change the symbol color according to one property and size with another one. How can I do it in QGIS? Thanks!
...
0
votes
0answers
14 views
Problem executing Mean Shift Segmentation
I have a problem executing the Mean Shift Segmentation in QGIS with Orfeo Toolbox. I put all the parameter to execute and then, nearly 5s after appear the message that SEXTANTE could not open the ...
0
votes
1answer
38 views
How to calculate Image boundary / footprint of satellite images using open source tools?
I'm referring to this question&discussion: How do I create a shapefile showing footprints of Rasters?
I need to create the polygon outlines of several single layer raster images, not the ...
1
vote
1answer
53 views
How do you scan/quantify vegetation using satellite images?
I am relatively new to GIS (about 4-5 months in) I did not receive any formal education about this so I am completely clueless about how to go about measuring/quantifying vegetation using satellite ...
1
vote
4answers
63 views
Get pixel value from a raster in a xy table
I'm trying to find a way to convert a raster (in my case it's a Landsat satellite image) into a table with 3 columns which would represent: 1) x coordinates (the so called "xllcorners" in ASCII ...
0
votes
0answers
24 views
QGIS affine rotation moves polygon
I am trying to rotate a polygon layer around a point but the affine tool keeps moving the polygon far away from where it needs to be. I'm using the affine calculations found in this stack exchange ...
2
votes
1answer
40 views
Can QGIS get the GPS Coordinates via the 'Windows Location Provider'?
Can Quantum GIS get the GPS Coordinates via the 'Windows Location Provider' in Windows 7/8 instead of reading a virtual com port?
If not, could this be developed as a Windows-specific plugin? (Is ...
4
votes
3answers
69 views
How to create scattered points in polygon
I have few polygons and I want to create few scattered well distributed point within the polygon. I am used to with ArcGIS and QGIS platform. How can I make it?
2
votes
2answers
51 views
How do I import UK Environment Agency Lidar data (.asc) into Quantum GIS
I have downloaded Lidar data from the UK Environment Agency as ESRI ASCII files but being a complete novice as far as GIS is concerned I do not know how to view them. Quantum GIS was recommended to me ...
0
votes
0answers
20 views
How to use GarminCustomMap Plugin for QGIS?
I want to take some polygon shapefiles and import them into a garmin gps unit. I am attempting to use the GarminCustomMap plugin in QGIS. There doesn't seem to be any help files avaialble to use this, ...
3
votes
2answers
63 views
Obtain all elevations points from a raster DEM
I need to obtain all elevation grid points from a raster DEM.
I see the steps required as:
Read in raster DEM (Arc Info Binary Grid format).
Create subset area using Points2One (see triangle area ...
1
vote
1answer
31 views
Combining polygon geometries with python and QGIS segfaults
I am trying to combine polygons, using Qgis 1.8, and every time I run this script in the python console, I get a segmentation fault. Here is the script:
from PyQt4.QtCore import *
iface = ...
0
votes
0answers
20 views
How to change value of an Line edit dynamically
I create a form in QT4 and compile with pyuic4. it create an form.py
I want to modify the value of the line edit dynamiclly with code.
I put this code in the form.py but never happen:
...
0
votes
0answers
16 views
QGIS on Mac OS X 10.8.2 and MS Azure SQL database connection
I'm running QGIS on a Mac (10.8.2) and want to get some data from a Microsoft SQL Azure database.
I'm confident the Azure side is fine and I have verified I can get to the Azure db using RazorSQL ...
0
votes
1answer
38 views
Make many lines in one layer (Python)
I what to create many lines with this code:
v_layer = QgsVectorLayer("LineString", "cable", "memory")
pr = v_layer.dataProvider()
seg = QgsFeature()
...
0
votes
2answers
58 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
2answers
67 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 ...
8
votes
1answer
98 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
73 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
2
votes
1answer
58 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 ...
3
votes
1answer
55 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
43 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
28 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"
...
0
votes
0answers
28 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
51 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!
