Mon Jul 19 02:55:34 CDT 2010
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:
From: Friedrich Romstedt <firstname.lastname@example.org>
To: Discussion of Numerical Python <email@example.com>
Sent: Sun, July 18, 2010 12:09:04 AM
Subject: Re: [Numpy-discussion] Crosstabulation
2010/7/17 Robert Kern <firstname.lastname@example.org>:
> On Sat, Jul 17, 2010 at 13:11, Friedrich Romstedt
> <email@example.com> wrote:
>> 2010/7/14 Ionut Sandric <firstname.lastname@example.org>:
>> 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
Thanks Robert, that clarifies a lot.
But still I don't understand how the crosstabulation shall work. What
are the "classes"?
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