Tagged Questions

1
vote
0answers
76 views

How to calculate weighted mean coordinates within polygons?

I'm using QGIS 1.8 on OSX 10.8.3. I have a polygon shapefile of all of the US state legislative districts. I also have a layer of points that are centroids of US Census Tracts, with a field for the ...
0
votes
0answers
34 views

Using random select FTools in QGIS

I wanted to ask about Random Select in Ftools for QGis, I have a polygon and wanted to randomly select within a specific subgrup of poligons that refers to an administrative boundary, but I haven´t be ...
2
votes
2answers
166 views

Couldn't load plugin fTools due an error when calling its classFactory() method

When I start qgis I get a python exception: Couldn't load plugin fTools due an error when calling its classFactory() method ... 309, in _import mod = _builtin_import(name, globals, locals, ...
1
vote
1answer
124 views

Why does ftools' difference tool fail?

I have an area polygon with rocks on it i want to use difference to map the soft (ground, not rocks) cover. to do that i try using the (ftools) vector>geoprocessing>difference getting an empty ...
1
vote
0answers
25 views

Access to Attribute join via command

I have 1.8 Quantum GIS, the menu "attribute join from the FTOOLS" no appears in the screen , is there a way to access via command?. thanks in advance
3
votes
1answer
197 views

How to calculate buffer surface that falls within another layer's borders

The image below shows what two selected layers. One contains a series of borders, and the other a series of buffers. I am trying to obtain the buffered surface within each of the borders in the ...
0
votes
0answers
22 views

Set buffer radius in metric units in qGIS [duplicate]

Possible Duplicate: What is up with QGIS buffer tool units? A similar question to this one has already been asked QGIS - Change unit of measure from degrees to meters, but none of the steps ...
2
votes
1answer
1k views

How to find polygons centroids? [duplicate]

Possible Duplicate: Get list of coordinates for points in a layer? Sorry for another basic question - my map is almost done but now my boss wants me to enter new outbreaks (that we don't ...