[Qgis-developer] Heatmaps integration

[aruntheguy at gmail.com]

Hello Paolo,

On Tue, Feb 14, 2012 at 3:00 PM, Paolo Cavallini <cavallini at faunalia.it>wrote:

> Hi all.
> Just tested the new plugin, quite nice. Where do I find more info about
> the algorithms used?
>

There is no specialized algorithm, the procedure in which pixel values are
computed is explained in the Context Help. Its just a linear assignment,
say for a buffer of 10 pixels, and decay of 0, the central pixel has a
value of 1, 2nd from center pixel has 0.9 and so n upto the 10th pixel with
value 0.  Its then added along for point by point. So the more the number
of points, the more the pixels' value.
http://idvux.wordpress.com/2009/08/21/heat-maps/ has a nice explanation of
various types of heatmaps (value interpolated, frequency). This tool
generated a frequency heatmap. So there is not much of algo space left.

Somethings like smoothing of boundaries can be done, but that would be more
of visual appeal without mathematical basis I think (correct me if wrong).



> Moreover, would it be possible to integrate it in the main interpolation
> command?
> Thanks.
>

The code is completely self contained, hence cannot be accessed from
outside.



-- 
Regards
Arunmozhi
Twitter: @tecoholic
Website: http://arunmozhi.in
IRC Nick: teco
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