similar to: Replacing values in a data.frame/matrix

I was wondering if someone can tell me the best way to search through a matrix and choose certain rows (based on certain conditions) to put into a separate matrix. What I have tried so far is very slow for a large dataset I'm working with. e.g., I have this piece of code to create a new matrix (newmat) based on my filtering conditions. Do I need to do this kind of thing where I keep

Can anyone explain this? I have a matrix with double components. It's taking up a lot of memory, so I want to multiply then turn it to integers. I'm pretty certain that there are only 2 decimal places, but I wanted to check by using modulo. E.g. mat = matrix(11:50/100, ncol=4,nrow=10) #Matrix with values out to the hundredths any((mat * 100)%%1!=0) But oddly enough it doesn't work.

Dear R gurus, I have the following code, but I still not know how to estimate and extract confidence intervals (95%CI) from resampling. Thanks! ~Adriana #data penta<-c(770,729,640,486,450,410,400,340,306,283,278,260,253,242,240,229,201,198,190,186,180,170,168,151,150,148,147,125,117,110,107,104,85,83,80,74,70,66,54,46,45,43,40,38,10) x<-log(penta+1) plot(ecdf(x),

I am trying to get a random matrix based on an original matrix called disperser.mx, with dimensions 30x73 When I write the following code: >scramble = sample (disperser.mx) >newmat = matrix(scramble, nrow=30) I get the following warning message and a very weird matrix with 30 rows but only 3 columns shown below: Warning message: data length [73] is not a sub-multiple or multiple of the

Duncan, Is this expected for x86_64-apple-darwin12 under Xcode 5? Using current llvm/compiler-rt/clang/polly/testsuite with dragonegg 3.4 branch, I see the warnings... % /sw/lib/gcc4.8/bin/gcc-4 -fplugin=/sw/lib/gcc4.8/lib/dragonegg.so -specs=/sw/lib/gcc4.8/lib/integrated-as.specs -fplugin-arg-dragonegg-enable-gcc-optzns -Ofast himenoBMTxpa.c himenoBMTxpa.c: In function ‘main’:

On Thu, Nov 21, 2013 at 07:37:46PM -0500, Jack Howarth wrote: > Duncan, > Is this expected for x86_64-apple-darwin12 under Xcode 5? Using current > llvm/compiler-rt/clang/polly/testsuite with dragonegg 3.4 branch, I see > the warnings... > > % /sw/lib/gcc4.8/bin/gcc-4 -fplugin=/sw/lib/gcc4.8/lib/dragonegg.so -specs=/sw/lib/gcc4.8/lib/integrated-as.specs

Dear Friends, I have a matrix of size 5000 X 20. The first two columns are indicator variables taking the value of either 0 or 1. Let us call the first two columns Y1 and Y2. I need to randomly sample 1000 rows with all the associated columns, in other words my new matrix should be of size 1000 X 20. I realize that using this command newmat <- mainmat[sample(1000,replace=F),] achieves

I'm looking to create a correlation matrix, but I have already obtained the correlations, which are stored in a vector. (Basically, I'm running a simulation which requires a correlation matrix, but I am simulating the various correlations.) My aim is to create a function that can take the vector, and fit the values into their respective locations in a correlation matrix. (The correlations

Hello, I am sure I am not the only person with this problem. I have a list with n elements, each consisting of a single column matrix with different row lengths. Each row has a name ranging from A to E. Here is an example: alph[[1]] A 1 B 2 C 3 D 4 alph[[2]] A 1 C 3 D 4 alph[[3]] A 1 D 4 E 5 I would like to create a matrix from the elements in the list with n columns such that the row names

Hi A toy example is probably the least ambiguous way of explaining what I'm trying to do. > library(ts) > zz<-list(a=rnorm(100),b=rt(100,3)) > zz.spec<-lapply(zz,spectrum,plot=F) > summary(zz.spec) Length Class Mode a 15 spec list b 15 spec list I'm looking for an elegant way to fetch components of the sub-lists a and b of zz.spec; e.g. to make a matrix

Hi folks, I am planning to write some more time-consuming matrix manipulations in c++. What is the experience with the existing c++ matrix libraries? Do you have some recommendations? Are some libraries more compatible with R than the others? All suggestions welcome! Best, Ott

Thank you very much for the example. I think interactively I could get something. But my obstacle is to write an R script that processes my set of data automatically. My difficulty is to extract the information that appears on the screen, when R is operated interactively, from a scripts. Let me go over some steps to make sure I am doing things right. Assume my data have been read into the matrix

I am a beginner and this is a naive question. I have the following data set. row column height 1 2 96 3 7 67 9 25 77 ...... I have a matrix of 50*100 data points and about 60% of them are zeros. I want to put the height data into the matrix according to their row and column numbers. does anybody have experience in setting up such matrix? Your help is highly appreciated. Jack LSU

Dear R Programmers, I am trying to run a Poisson regression on all pairs of variables in a data set and obtain the permutation distribution. The number of pairs is around 100000. It seems my code will take weeks to run, unless I try something else. Could you give me any suggestions on how to improve the speed of the code below, or any general suggestions on how I may accomplish this task. Thanks

Dear all, I want to get a series of boxplots (grouped by two factors) and I want to overlay the original observations and the following code does almost what I want: library(ggplot) ddf <- data.frame(x=factor(rep(LETTERS[1:4], each=30)), y = runif(120,0,10), grp = factor(rep(rep(1:3, 10), 4))) ggplot(ddf, aes(x, y, colour=grp)) + geom_boxplot() + geom_point() Yet the position of the points

Hi! I am doing a two sample permutation test and trying to find confidence interval. perm.test() seems can do that but when the vector contains negative numbers it occurs an error. And for perm.test(x,y), elements in x can't be more than in y. I am wondering how I can fix these two problems? Thanks a lot. -- View this message in context:

Hi, I ran into an odd problem with the print command for R-2.0 on a windows machine. The icelandic character thorn (??,??) which is included in in the Latin-1 character set [iso/8859-1 char# 222 (upper case) and #254 (lower case)] prints out incorrectly. Instead of getting the correct character I get the octal codes for upper and lower case thorn (\336 or \376). This only happens on a windows

Hello, I am using logistic discriminant analysis to check whether a known classification Yobs can be predicted by few continuous variables X. What I do is to predict class probabilities with multinom() in nnet(), obtaining a predicted classification Ypred and then compute the percentage P(obs) of objects classified the same in Yobs and Ypred. My problem now is to figure out whether P(obs) is

Dear R list, I have discovered a seemingly peculiar feature when using a matrix to index itself (yes, this is strange code, which I have now modified to be more reasonable). #this makes sense s <- matrix(1:3,nrow=1) s[s] #all three elements are shown #but when I try s <- matrix(1:2,nrow=1) s[1] #fine, the first element is shown s[2] #fine, the second element is

Hi everyone, I am somewhat new to R and I am trying to write a permutation function such that it inputs a character vector and from an arbitrary length "n" which is the length of the combinations for the character vector. I know there are R packages for permutation but this is for an assignment. So far this is what I have: alphabet =