[Numpy-discussion] Crosstabulation

[Friedrich Romstedt]

2010/7/17 Robert Kern <robert.kern at gmail.com>:
> On Sat, Jul 17, 2010 at 13:11, Friedrich Romstedt
> <friedrichromstedt at gmail.com> wrote:
>> 2010/7/14 Ionut Sandric <sandricionut at yahoo.com>:
>> 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