Hi Friedrich:
For land-use a class would be for example forest, other would be orchard etc.
For Slope gradient I would have values which <3 and between 3 and 7 etc. So, I
will have 2 raster data with, let's say, 3 classes each: forest, orchards and
built-up area and for slope gradient: 0-3, 3-15, 15-35. The cross-tabulation
analysis should give me a table like:
forest orchards built-up
0-3 10 20 15
3-15 5 10 20
15-35 5 15 15
where the numbers represents all the common cells, for example: 10 cells with
forest correspond to 10 cells with 0-3 slope gradient interval and so on
(by cells I mean the pixel from a raster data)
The analysis is better illustrated here:
http://webhelp.esri.com/arcgisdesktop/9.2/index.cfm?TopicName=tabulate_area
Ionut
________________________________
From: Friedrich Romstedt
On Sat, Jul 17, 2010 at 13:11, Friedrich Romstedt
wrote: 2010/7/14 Ionut Sandric
: I'm afraid also Zach does not understand what you are talking about ... So my first question (please bear with me) would be: What's a dem? Digital Elevation Map.
(n/a in my dictionary) And sorry for the cross-talk on the other first post by you ...
And by slope gradient you mean second derivative?
No, the first derivative. "Slope gradient" is a reasonably common, albeit somewhat redundant, idiom meaning the gradient of an elevation map.
Thanks Robert, that clarifies a lot. But still I don't understand how the crosstabulation shall work. What are the "classes"? Friedrich _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion