[R] contour algorithm

[R. Michael Weylandt]

The C implementation of the algorithm is here:

http://svn.r-project.org/R/trunk/src/main/plot3d.c

(grep filledcontour) but I don't see a reference other than to Ross Ihaka.

Hope this helps,
Michael

On Sat, Apr 21, 2012 at 9:21 PM, Stoch astic <asticstoch at gmail.com> wrote:
> First time user, so sorry if I don't understand protocol.. Anyway, I have
> created a data frame consisting of pearson's R values at various x and y
> coordinates and then plotted this using filled.contour. My data is similar
> to fMRI data except that it is a surface map reconstructed from
> histological sections. I like the results but would like to know how
> contours were detected. Google search provides me various sources claiming
> the algorithm used is undocumented. For example:
>
>
> http://wipaed.wiso.uni-goettingen.de/~holdenb1/R/library/base/html/contour.html
> "Draws contour lines for the desired levels. There is currently no
> documentation about the algorithm. The source code is in
> `$RHOME/src/main/plot.c'."
>
>
> Does anyone know where or how I can find the method by which contours are
> calculated?
>
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>
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