Tagged Questions
3
votes
1answer
185 views
Estimating cline width at multiple points along a trait gradient
In the map below I have 66 (green) points along the midpoint (0.5) for an allele frequency cline across the region (see map). I created the points by placing a point every 25 km along the 0.5 allele ...
4
votes
2answers
1k views
How can I compare two point shapefiles that contain lat/longs and compute distance?
Greetings everyone, I have 2 sets of point shapefiles in ArcGIS (group A and B), each set has around 1000 entries that contain lat/long. What I want to do is compare Group A against Group B and figure ...
6
votes
7answers
2k views
Extract raster values at points
How can I extract values from a raster by points. I prefer not in Arcgis. I prefer in Qgis or Mapwindow or other open source gis.