similar to: Is it possible to read jpeg files into R?

Dear R helpers, I wish to use the "sum" operator for each row of a data frame. However, it appears that the operator acts on the entire data frame, over all columns. What is the best way to obtain row- wise operation? The following code shows my attempts so far, and their problems:- test1=array(rbinom(120,1,0.5),c(20,3)) test1[,3]=NA sum(test1[,1:2]) test1[,3][sum(test1[,1:2])>=2]=1

Jonathan, Try making a list instead of an array. See ?list. Also, did you look into random forests? I'm not sure what you want to do, but there might be methods there to do some of the work for you. Sean On 3/19/04 1:12 PM, "Jonathan Williams" <jonathan.williams at pharmacology.oxford.ac.uk> wrote: > I would like to collect the trees grown by rpart fits in an array,

Oh dear - I joined the R help mailing list last week, in order to ask a specific question. I did not realise that I would start to receive all e-mails to and from the mailing list. Is there a way of letting me receive only the answers to my own questions? If not, then can you remove me from the mailing list? Thanks, Jonathan Williams Jonathan Williams OPTIMA Radcliffe Infirmary Woodstock Road

I am trying to analyse recurrent failure times using survfitr from the survrec package. To do this, I need to "Create a survival recurrent object" using Survr. But, when I do this, I get an error "Error in Survr(r1d[, 1], r1d[, 5], r1d[, 6]) : data doesn't match". Here, r1d[,1] is the identifier for each case, r1d[,5] is the time of recurrence, r1d[,6] is the status

I am having great difficulty plotting what should be a simple graph. I have measured 1 'y' and 5 'x' variables in each of two groups. Linear regression shows significant differences in the slopes of the regression for each 'x' variable between the two groups. All that I want to do is to plot one graph that shows the scatterplot for the three groups (each group represented

Dear R-helpers, I have found a slightly annoying problem when trying to plot lines on graphs. I first created my data using tapply, thus:- y1=as.vector(fit1$coef$random$id) x1=tapply(o1,id,median,na.rm=T) x2=tapply(o2,id,median,na.rm=T) #then I plot the data, thus:- plot(x1[x2==0],y[x2==0]) #if I now try to fit the linear regression, R 'hangs up'

Dear R helpers, I would like to ask why polr occasionally generates results that look very odd. I have been trying to compare the power of proportional odds logistic regression with the Wilcoxon test. I generated random samples, applied both tests and extracted and compared the p-values, thus:- library(MASS) c1=rep(NA,100); c2=c1 for (run in 1:100) { dat=c(rbinom(20,12,0.65),rbinom(20,12,0.35))

Dear R helpers, I have a curious problem, which is that a program I have written in R crashes R, unpredictably. When I say that the program crashes R, I mean that it causes R to terminate, completely. But, the operating system (Windows) continues OK. The program loops around a randomForest regression. I am trying to use randomForest to predict the diagnosis for a set of patients with dementia. I

Jonathan, Is there any possibility for you to send me the data, and/or the code? I and others have seen similar problems before, but not reproducible on the current version, at least on the NT and Linux boxes that I have access to. As Thomas said, it's difficult to nail these kinds of problems. Having reproducible data and code, at least, can help. (It's no help that I'm no expert

I have a time series of data from an electroencephalogram (EEG). I wish to filter the data to get rid of 50Hz mains 'hum'. I have 'designed' a combination bandpass and notch filter using a web- site. The site returns the filter in "ANSI C" source code. It is:- /* Digital filter designed by mkfilter/mkshape/gencode A.J. Fisher Command line:

Is there a good way in R to impute values which exist, but are less than the detection level for an assay? Thanks, Jonathan Williams OPTIMA Radcliffe Infirmary Woodstock Road OXFORD OX2 6HE Tel +1865 (2)24356

Dear R-helpers, I want to try to extract residuals from a multi-level linear mixed effects model, to correlate with another variable. I need to know which residuals relate to which experimental units in the lme. I can show the labels that relate to the experimental units via the command ranef(fit0)$resid which gives: 604/1/0 -1.276971e-05 604/1/1 -1.078644e-03 606/1/0 -7.391706e-03 606/1/1

Dear R-helpers, I am having difficulty making R plot only integer labels on the x-axis of a simple graph. I want to plot the median values of a score on each of three occasions. Non-integer occasions are impossible. But, R keeps labelling the x-axis with half-occasions, despite my attempts to stop this using the "xaxs" and "xaxp" parameters of 'plot'. p1=c(1,2,3);

PTAk_1.1-1 ( Principal Tensor Analysis on k modes) has been released on CRAN A multiway method to decompose a tensor (array) of any order, as a generalisation of SVD also supporting non-identity metrics and penalisations. 2-way SVD with these extensions is also available. The package includes also some other multiway methods: PCAn (Tucker-n) and

PTAk_1.1-1 ( Principal Tensor Analysis on k modes) has been released on CRAN A multiway method to decompose a tensor (array) of any order, as a generalisation of SVD also supporting non-identity metrics and penalisations. 2-way SVD with these extensions is also available. The package includes also some other multiway methods: PCAn (Tucker-n) and

Dear R-help I want to display an image file in a new plot frame. SVG is my preferred format, but I can also consider PNG, GIF, JPEG, TIFF, and PPM (from ImageMagick). By way of background (although not material to this posting), the image file is generated by a call to 'dot' (part of the 'Graphviz' suite) after the required .dot file has been produced using hand-crafted R code.

Can someone advise me what the most sensible way is to read jpeg images? For our work with image analysis and eye-tracking we have been using the rimage package, on both Macs and Windows PCs. But while setting up a new Windows machine yesterday, I see that rimage is regarded as orphaned, and no Windows binary is available. I eventually found an old zip file for the package, so I

Is it possible to plot an image (currently a jpeg) in the margins? Thanks, Kari [[alternative HTML version deleted]]

Hi, I have some code that uses rJava. One of the Java side methods returns a byte[] representing the bytes from a PNG image. What I'd like to do is to be able to bring up the PNG on the R side (I can bring up a Swing window to show the PNG but I want to avoid that). I have looked at the pixmap and rimage packages but don't seem to be able to work out how I'd go about this (or if

I'm interested in digitizing some scanned time series, and looking for a solution that is easy and flexible. I thought I might be able to use R's locator() if I could get the image into a device. I noticed that there are some packages like (rimage), but it (a) doesn't seem to be available for the Windows version and forces me to upgrade a bunch of libraries for my linux system. It