On 7/19/06, hadley wickham <[EMAIL PROTECTED]> wrote: > > I would like to fit a distribution to each of the peaks in a histogram, such > > as this: > > http://photos1.blogger.com/blogger/7029/2724/1600/DU145-Bax3-Bcl-xL.png > > As a first shot, I'd try fitting a mixture of gamma distributions (say > 3), plus a constant term for the highest bin. You could do this using > ML. If the number of peaks is truly unknown, this will be a little > trickier but still possible and you could use the LRT to chose between > them.
Can you be a bit more excact? I a biologist and relatively new to R > > > Integrate the area between each two peaks, using the means and widths of the > > distributions fitted to the two peaks. I will be using the integrate > > function > > Why do you want to do this? I am measureing the amount of DNA in cells, and I need to know the percentage of cells in a part of the cell cycle; that the percentage of cells in the first peak, in the second peak and so on. I want to integrate the area between to two cells, because that apparently is how its none (as far as I can tell from the literature) > > > > > The histogram is based on approximately 15000 events, which makes Mclust and > > pam (which both delivers the information I need) less useful. > > If you have unbinned data, it would be better (more precise/powerful) > to use that. It very probably is better, but mclust had no result after running for at least 2 hours (I terminated the function after two hours), and as I generate 50-100 datasets, such as the one used for the histogram, as week, I would like to find a faster solution > > Regards, > > Hadley > Thanks Ulrik -- Blog: http://ulrikstervbo.blogspot.com ______________________________________________ [email protected] 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.
