similar to: Suggestion about "R equivalent of Splus peaks() function"

Hello list! 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 . The peaks are identified using Petr Pikal peaks function ( http://finzi.psych.upenn.edu/R/Rhelp02a/archive/33097.html), but after that I am quite stuck. Any idea as to how I can: Fit a distribution to each peak Integrate the

I've been asked in private, (and am replying BCC to the asker), >> I saw your post on the R-help archives page about the possibility of >> porting a function from S-Plus called peaks() to R. I am looking for >> some way to locate peaks in a simple x,y data set, and thought that R >> might be the way to go. "of course" it is the way to go, don't get

Hello all, I have some histograms of amount of DNA in some cells (DU145 cells overexpressing Bax and Bcl-xL for those who wish to know). The histograms show not only two peaks as expected, but three, indicating that some cells have more than normal amounts of DNA. I am interested in knowing how much of the cell populations are in each peak as well as between. I am not really sure how to go

If there something available in R that has the functionality of the S-PLUS peaks() function? Thanks, Mirka

Hi, all. Does anyone have an equivalent to Splus "peaks", which finds local maxima (with locality defined by a parameter "span")? I thought I'd check whether anyone has done it already before trying to put something together myself. Thanks, Matt Wiener -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read

Dear useRs, I have a curve which is a mixture of Gaussian curves (for example UV emission or absorption spectrum). Do you have any suggestions how to implement searching for optimal set of Gaussian peaks to fit the curve? I know that it is very complex problem, but maybe it is a possibility to do it? First supposement is to use a nls() with very large functions, and compare AIC value, but it is

Hello, Thank you to all those great folks that have helped me in the past (especially Dennis Murphy). I have a new challenge. I often generate time-series data sets that look like the one below, with a variable ("Phase") which has a series of flat-topped peaks (sample data below with 5 "peaks"). I would like to calculate the phase value for each peak. It would be great to

http://r.789695.n4.nabble.com/file/n3312061/x_and_y_values.txt x_and_y_values.txt I have the absorbance values form HPLC Chromatogram. I need to find the peaks in datapoints and area under each peak. I am not sure how how to find the peaks, I tried couple of libraries and peak function but they return me a list of values which when computed from area turns out to be huge nnumbers. In the

I am looking for a function in R that is equivalent to the function "peaks" in Splus. This function gives the local maxima of a vector. I do not find it using the help and I 'm not sure it exits in R. Could someone help me ? Thanks, Herve Cardot -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read

Hello all I'm trying to do a simulation that involves identifying the minimum point between two peaks of a (usually) bimodal distribution. I can do this easily if there are only two peaks: CnBdens<-density(Ys/Xs) #probability density function for ratio of Ys to Xs for(p in 1:512) ifelse(CnBdens$y[p]>CnBdens$y[p-1],peak1<-p,break) #identifies first peak in probability

This is probably a trivial question, but I did not see it in the FAQs. Perhaps I simply need to be pointed to some URLs. In any case, I have some sampled data that has peaks, and I would like to extract peak height, location, and width, according to almost any statistical model. Gaussian would seem to make the most sense. There can also be "steps" increasing the amplitude over a

Full_Name: Benny van der Vijgh Version: 2.7.2 OS: Windows Vista Submission from: (NULL) (194.171.252.108) The return value of peaks() in package splus2R is not consistent. This is because of the call to max.col() without additional parameters which peaks() makes. max.col() has a parameter 'ties.method' which specifies how ties are handled, with "random" by default. This means

I have a seasonal time series. I want to calculate the annual mean value of the time series at its peak (say the mean of the three values before the peak, the peak, and the three values after the peak). The peak of the time series might change cycle slightly from year to year. # E.g., nPts <- 254 foo <- sin((2 * pi * 1/24) * 1:nPts) foo <- foo + rnorm(nPts, 0, 0.05) bar <- ts(foo,

I'm sure there must be various peak-finding algorithms out there. Not knowing of any, I have written one myself*, but I thought I'd ask to see what's out there. Basically, I have a 2-dimensional data set and I want to identify local peaks in the data, while ignoring "trivial" peaks. My naive algorithm first identifies every peak and valley (point of inflection change

Hello, it wanted to know how I can extract of a dates frame the values peaks according to an interval that I establish. For example if dates are: 1 23 2 4 3 56 4 7 5 99 6 33 extract the date i wanted to divide into intervals of 2 an d to take alone the numbers 23, 56 and 99 of those 3 intervals. Thanks Ruben

Greetings all, I am using Fourier analysis to search for periodicities in IP network traffic by generating periodograms and then visually examining them for large, distinct peaks. However, in many cases it is not readily apparent where there are periodicities. I have no experience with discrete maths so I've come up against a block here: How do I define what the "noise floor"

Hi, I have a problem of estimating a mixture of two normal distributions. I need to find the starting points automatically, since this is a part of a larger piece of image processing code. I found the mix2normal1 function in VGAM package that mentions a method of finding starting values for mu1 and mu2 but refers the reader to a book by Everitt and Hand. Unfortunately, I do not have an easy

I need to process some datasets where the configuration information was stored in .INI-like files, i.e., text files with sections like this: [Section1] var1=value1 var2=value2 [Section2] A=value3 B=value4 ... >From Google and other searches I haven't found any package, or function within a package, that reads .INI files into an R list, or other data structure. Any suggestions, or

Grrr ... new trial with code here: http://pastebin.com/RjHNNG9J Maybe the amount of inline-code prevented posting? Hello, I am writing a simple peak detector and it works quite well ... however there's one special case below, that I can't get my head wrapped around ... the problem is in the "Deal with not fully qualified peaks at the sequence extremes" section, but I cannot

I've always been frustrated that R never puts a label on the column name for a column of row names. This is usually the "key" in a database table, and it sure would be nice to carry a "key" name along with the data instead of the field being blank. So, why is it a good idea for it to be blank? ?write.csv says this: CSV files By default there is no column