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 `$RHOME/src/main/plot.c'." Does anyone know where or how I can find the method by which contours are calculated? [[alternative HTML version deleted]]
The C implementation of the algorithm is here: http://svn.r-project.org/R/trunk/src/main/plot3d.c (grep filledcontour) but I don't see a reference other than to Ross Ihaka. Hope this helps, Michael On Sat, Apr 21, 2012 at 9:21 PM, Stoch astic <asticstoch at gmail.com> wrote:> First time user, so sorry if I don't understand protocol.. Anyway, I have > created a data frame consisting of pearson's R values at various x and y > coordinates and then plotted this using filled.contour. My data is similar > to fMRI data except that it is a surface map reconstructed from > histological sections. I like the results but would like to know how > contours were detected. Google search provides me various sources claiming > the algorithm used is undocumented. For example: > > > http://wipaed.wiso.uni-goettingen.de/~holdenb1/R/library/base/html/contour.html > "Draws contour lines for the desired levels. There is currently no > documentation about the algorithm. The source code is in > `$RHOME/src/main/plot.c'." > > > Does anyone know where or how I can find the method by which contours are > calculated? > > ? ? ? ?[[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.
On 12-04-21 9:21 PM, Stoch astic 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'."That's a very old copy of the help page. You're generally better off using the ones installed with R, or the ones on CRAN (cran.r-project.org/web/packages) rather than what Google finds somewhere. Duncan Murdoch> > > Does anyone know where or how I can find the method by which contours are > calculated? > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.