Displaying 20 results from an estimated 1000 matches similar to: "peaks"
2004 Jan 14
1
R equivalent of Splus peaks() function?
If there something available in R that has the
functionality of the S-PLUS peaks() function?
Thanks,
Mirka
2002 Feb 20
3
importing images
I would like to import "tif" images in R and I do not find any
function that can do that. In Matlab there exists the function "imread"
that can read the most known images format. Does a similar function
exist for R ?
Thanks in advance
--
Herve CARDOT
____________________________________________________________
Unite Biometrie et Intelligence Artificielle, INRA Toulouse
BP
2011 Feb 18
1
Find peaks in dataset(x,y) and area for each peak
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
2009 Oct 07
1
inconsistency in return value of peaks() {splus2R} (PR#13988)
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
2006 Jul 20
3
How do I modify an exported function in a locked environment?
Running R.app on Mac OS X 10.4
> version
_
platform powerpc-apple-darwin8.6.0
arch powerpc
os darwin8.6.0
system powerpc, darwin8.6.0
status
major 2
minor 3.1
year 2006
2006 Jul 20
3
How do I modify an exported function in a locked environment?
Running R.app on Mac OS X 10.4
> version
_
platform powerpc-apple-darwin8.6.0
arch powerpc
os darwin8.6.0
system powerpc, darwin8.6.0
status
major 2
minor 3.1
year 2006
2010 Dec 23
1
Finding flat-topped "peaks" in simple data set
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
2006 Jul 15
1
Find peaks in histograms / Analysis of cumulative frequency
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
2013 Aug 29
1
Problem with "Peaks" package - followup…
Hi,
I apologize for not following the posting rules?
Here is the text from my previous post:
"I started evaluating the 'Peaks' package a couple of months ago and found it to be quite
useful. Getting back to it last week I had to set up my R environment due to hardware
changes again. The Peaks package loads with no problem.
After successfully reinstalling all packages (RedHat
1998 Mar 26
1
R-beta: problem with locfit
I installed the locfit package under Linux (gcc 2.7.2). Installation
was ok but
> x <- runif(200)
> y.compl <- 10*x*x*rgamma(200,3)
> med.y <- median(y.compl)
> cens <- ifelse(y.compl<=med.y,1,0)
> y <- cens * y.compl + (1-cens)*med.y
> library(locfit)
> m <- locfit(y~x,cens=cens,family="gamma")
/usr/local/src/R-0.61.1/bin/R.binary: can't
2006 Jan 04
1
Selecting significant peaks in periodograms
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"
2007 Jul 25
2
initalizing and checking validity of S4 classes
Dear useRs and wizaRds,
I am currently developing a set of functions using S4 classes. On the way I encountered the problem exemplified with the code below. For some reason the 'validity' method does not seem to work, i.e. does not check for errors in the specification of the slots of the defined class. Any hints?
My understanding of the whole S4 system was that validity checks are made
2011 Apr 22
3
[LLVMdev] copy instructions
This is a simple SSA code generation 101 question.
If I follow the IR code generation techniques in the Dragon book the
statement
x = y + z
would translate into something like this in SSA/LLVM
%0 = add %y, %z
%x = %0
Obviously "copy instructions" like %foo = %bar are senseless in SSA
since %foo and %bar are immutably fixed to the same value and there
is no need for two aliases
2007 Feb 08
1
Suggestion about "R equivalent of Splus peaks() function"
In 2004 there was this R-Help posting from Jan 2004:
http://finzi.psych.upenn.edu/R/Rhelp02a/archive/33097.html
R equivalent of Splus peaks() function?
The peaks function there has worked well for me on a couple of projects, but
some code using "peaks" failed today, which had worked fine in the past.
I was looking for a peak in a test case that was a sine curve over one
2001 May 29
2
Using "R" to find peaks in sampled data
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
2003 Nov 26
5
multiple peaks in data frame
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
2006 Jul 19
3
Fitting a distribution to peaks in histogram
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
2015 Feb 26
3
iterated lapply
Would introducing the new frame, with the call to local(), cause problems
when you use frame counting instead of <<- to modify variables outside the
scope of lapply's FUN, I think the frame counts may have to change. E.g.,
here is code from actuar::simul() that might be affected:
x <- unlist(lapply(nodes[[i]], seq))
lapply(nodes[(i + 1):(nlevels - 1)],
2015 Feb 24
3
iterated lapply
From: Daniel Kaschek <daniel.kaschek at physik.uni-freiburg.de>
> ... When I evaluate this list of functions by
> another lapply/sapply, I get an unexpected result: all values coincide.
> However, when I uncomment the print(), it works as expected. Is this a
> bug or a feature?
>
> conditions <- 1:4
> test <- lapply(conditions, function(mycondition){
>
2007 Oct 13
2
How to identify the two largest peaks in a trimodal distribution
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