similar to: head.matrix() unintelligent

Hi guys, one of the questions where you need a real human instead of a search engine, so it would be great if you could help. I have a matrix of z-scores which I would like to filter, sometimes columnwise, sometimes rowwise. Data looks like this: Allstar hsa.let.7a hsa.let.7a.1 hsa.let.7a.2 2 0.87 0.79 -0.57 1.07 3 0.67 -1.14 -0.78 -0.95 4

Hi, I would like to generate a correlation matrix with a particular structure. For example, a 3n x 3n matrix : A_(nxn) aI_(nxn) bI_(nxn) aI_(nxn) A_(nxn) cI_(nxn) aI_(nxn) cI_(nxn) A_(nxn) where - A_(nxn) is a *specified* symmetric, positive definite nxn matrix. - I_(nxn) is an identity matrix of order n - a, b, c are (any) real numbers Many attempts have been unsuccessful because a

Dear R Group: How to import multiple csv files and merge into one dataset. Thanks and Regards, Xing [[alternative HTML version deleted]]

I thought the "apply" functions are faster than for loops, but my most recent test shows that apply actually takes a significantly longer than a for loop. Am I missing something? It doesn't matter much if I do column wise calculations rather than row wise ## Example of how apply is SLOWER than for loop: #rm(list=ls()) ## DEFINE VARIABLES mu=0.05 ; sigma=0.20 ; dt=.25 ; T=50 ;

Hi all, I wonder if this kind of questions are ok in this list... Quick question: What does it mean than the rank of the QR decomposition of a NxN matrix is N-1 ? m: NxN matrix qr(m)$rank equal to (N-1) Long version: I'm doing a manova on a matrix of 10 variables and 16 observations. > dim(tmp) [1] 16 10 > fit <- manova( tmp ~ treatment*mouse ) >results <-

dear allI have a data set with three types (Tree, Sapling, Seedling). I have estimated the correlation values. now i need to bring all the correlation values in a table like the one i have shown in attached file with R codes.could you please give me idea on this problem thanking you MSNepal _________________________________________________________________ Hotmail: Trusted email with

R Version 2.12.1 (2010-10-15) vs 2.12.0 has slowed down 8 fold for dual core and 17 fold for dual-core-dual-processor Macs. I have checked this result on 3 different macs using the following R-script: Using Version 2.12.0 on a dual core dual processor Mac: > source("http://www.bio.umass.edu/biology/kunkel/pub/R/CuriousResult.R") matrix multiplication 43.543 1.308 14.788

The code below create an nxn upper triangular matrix of one's. I'm stuck on finding a more efficient vectorized way - Thanks. --Dale n <- 9 data <- matrix(data=NA, nrow=n, ncol=n) data for (i in 1:n) { data[,i] <- c(rep(1,i), rep(0,n-i)) } data

I am having a hard time understanding just what 'sweep' does. The documentation states: Return an array obtained from an input array by sweeping out a summary statistic. So what does it mean "weeping out a summary statistic"? Thank you. Kevin

Hi, I tried looking through google search on whether there's a way to computer the median for each row of a nxn matrix and return the medians for each row for further computation. And also if the number of columns in the matrix are even, how could I specify which median to use? Thank you very much! -- Edward Chen [[alternative HTML version deleted]]

Dear Rusers, Trying to reduce my for loops addiction, could somebody tell me if there are ways to simplify (and perhaps accelerate ?) the following line for (i in 1:N) for (j in 1:N) m[i,j] = b[i]-b[j]; (where m is a NxN matrix and b a vector of length N) Thanks for any hint.

Hello Spse I have a matrix, say 1 2 3 4 5 6 7 8 9 and I would like to expand it by repeating rows within the matrix, to get, if the repeating factor is 2, say: 123 123 456 456 789 789 (or columnwise as well) . There must be a smart way of doing that? Many thanks Juhana Vartiainen juhana.vartiainen at labour.fi -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-

Hello everyone I hope Im not bothering you all again. I have just begun to use R and so Im not yet familiarized with it.. I ve got an assignment which consists in calculating the area of a circle given a certain radius and center using the monte carlo method, which means that I have to plot a circle given its parameters. Limit the area inside it...with as many sample points as possible...and

Since format, i.e., format.default(.), is a pretty basic function I thought I'd ask before just changing it... aa <- cbind(1:7, rnorm(7)) format(aa) or format(aa, digits=7) looks like [,1] [,2] [1,] " 1.0000000" " 0.2406669" [2,] " 2.0000000" "-0.4973221" [3,] " 3.0000000" " 0.4672260" [4,] "

Hi all, I'm have a matrix (X) with observations as rows and parameters as columns. I'm trying to exchange all missing values in a column by the column mean using the code below, but so far, nothing happens with the NAs... Can anyone see where the problem is? N<-nrow(X) # Calculate number of rows = 108 p<-ncol(X) # Calculate number of columns = 88 # Replace by columnwise

Is there a function or an easier way to computer geometric means of each rows in a nxn matrix and spit out in an 1xn matrix ? -- Edward Chen [[alternative HTML version deleted]]

Hi all, Here is my problem: I have 3 matrices , A, B, C. Each is an nXn matrix. I need to create matrix D such that : D[i,j]= (A[i,j]+B[i,j]+C[i,j])/3. Being a newbie this is proving to be a challenge. Any ideas on how best to accomplish this? Thanks! Anjan -- ============================= anjan purkayastha, phd bioinformatics analyst whitehead institute for biomedical research nine cambridge

Dear All, I am struggling with the following problem: I am given a NxN symmetric matrix P ( P[i,i]=0, i=1...N and P[i,j]>0 for i!=j) which stands for the relative distances of N points. I would like use it to get the coordinates of the N points in a 2D plane. Of course, the solution is not unique (given one solution, I can translate or rotate all the points by the same amount and generate

Respected Sir, I am trying to import excel file into R, but I need to truncate some columns from the original file. How to delete unwanted columns when I import data from excel file. How to use cor.test for the data when I want the output rowwise. How to do grouping and use cor.test on that data I need some help regarding how to calculate the correlation. I don't know whether you

Hi everybody, i'm dealing with some percentage tables, of which i should test rowwise if the entries are sgnificantly equal or not. Namely, on row 1, test H0: element 1= element2, H0: element 1= element3...H0: element 2= element3...H0: element n-1= element n. The same on the other rows. Anybody knows how this can be done in quick way? I don't have large matrices, but it seems quite