similar to: Extracting diagonal matrix

Displaying 20 results from an estimated 3000 matches similar to: "Extracting diagonal matrix"

2012 Mar 08
4
Correlation between 2 matrices but with subset of variables
Dear All, I have two matrices A (40 x 732) and B (40 x 1230) and would like to calculate correlation between them.  I can use: cor(A,B, method="pearson") to calculate correlation between all possible pairs. But the issue is that there is one-many specific mappings between A and B and I just need to calculate correlations for those pairs (not all). Some variables in A (proteins, say p1)
2008 Jul 15
2
Problem installing R on openSUSE 10.3
Dear All, I am trying to install R 2.7 on my openSUSE 10.3. I have faithfully followed instruction at http://cran.r-project.org/bin/linux/suse/ReadMe.txt. I have downloaded all the RPMs but still R complains about: libtcl8.4.so is needed by R-base-2.7.1-6.1.i586 I searched for this library and found a one, tcl-8.4.15-22.i586.rpm at openSUSE distribution site and installed. But R still complains
2008 Jul 10
2
false discovery rate !
Dear All, It is not a typical R question (though I use R for this) but I thought someone will help me. For the list of P values, I have calculated FDR using p.adjust() in R (bioconductor). But my FDR values are same for all the P values. When do we get same FDR values? Does the smallest P values should less than 1/N? (where N is the number of P values) Thanks in advance. Kind regards, Ezhil
2009 Sep 11
3
Working with large matrix
Dear All, I have large matrix (46000 x 11250). I would like to do the linear regression for each row. I wrote a simple function that has lm() and used apply(mat,1,func). The issue is that it takes ages to load the file and also to finish the lm. I am using LINUX 64 bit with 32G mem. Is there an elegant and fast way of completing this task? Thanks in advance. Kind regards, Ezhil
2007 Apr 27
2
Scatter Plot in R - Help
Dear All, I am using the following commands to do the scatter plot of two vectors, say X and Y. plot(X,Y, col="blue") abline(a=1,b=1, col="red") abline(a=-1,b=1, col="green") I would like to split the scatter plot into 3 part with 3 different colors: (i) points lies between 2 lines, (ii) points above line 1, and (iii) points below line 2. I am struggling to do
2005 Oct 26
3
Storing graphics output in PNG format.
Dear All, How can I store hist() or any plot output graphics in PNG format? I tried with bitmap() but not getting the result. Appreciate your help on fixing this. Thanks in Advance. Regrads, Ezhil
2008 Nov 21
2
Calculating correlation for a big matrix
Dear All, I have a matrix of size 10000 x 50. I would like to calculate all possible pair-wise correlation coefficient (5x10^7 combinations) using cor(). How can I efficiently calcualte and save the result in a matrix? Thanks in advance. Kind regards, Ezhil
2009 Sep 07
2
Averaging rows if a condition is true.
Dear All, I have matrix (50000 X 60) of subjects and their responses to a set of questions. All responses are classified into categories (500). I would like to average all subject's responses for each category. I wrote a code using a for loop but is not working. Could please tell me what's wrong with the code? I guess, there is a elegant R way of doing the same thing. Thanks in advance.
2006 Jun 27
1
Boxplot questions.
Dear all, I am having a data for 2 different treatments with different time points. So, I used the following code to plot the boxplot and also to do anova. T11 <- c(280, 336, 249, 277, 429) T12 <- c(400, 397, 285, 407, 313) T13 <- c(725, 373, 364, 706, 249) T21 <- c(589, 257, 466, 248, 913) T22 <- c(519, 424, 512, 298, 907) T23 <- c(529, 479, 634, 354, 1015) obs <- c(T11,
2007 Mar 28
5
Large matrix into a vector
Hi, I have a matrix HR(9x27). I would like to make a single vector with elements: t(HR[,1]) followed by t(HR[,2]) and then t(HR[,3] ... etc. Is there any neat way of converting this matrix into a vector rather doing something like c(t(HR[,1]), t(HR[,2]), t(HR[,3]) ..)? Thanks in Advance. Kind regards, Ezhil ____________________________________________________________________________________
2006 May 29
2
newbie question: ROW average
Dimitris Rizopoulos wrote: > look at ?rowMeans; you can also use "apply(mat, 1, mean)" but > rowMeans() is better. By my reading of the question, this is not what Ezhil wants. He said: ``I have a 992 x 74 matrix. I would like to form a new matrix by averaging each 4 rows from the original one.'' I.e. he wants (I think) the first row of the new matrix to be the
2008 Nov 25
3
Line color based on data values?
Hi all Does anyone know if it is possible when plotting a line or scatter plot, to selectively color the data points based on the data value? i.e. if plotting say the percentage change in stock price movements, to color +ve points in green and -ve points in red? And extending this to a user-defined range of colors based on the quartile of the data points? Thanks Rory Rory Winston RBS Global
2010 Oct 27
2
add diagonal line
Hi, I would like to add a line on the diagonal of a covariance matrix, is there a quick way to do it besides abline? Thanks! -- Marcelo Andrade de Lima UNIFESP - Universidade Federal de São Paulo Departamento de Bioquímica Disciplina de Biologia Molecular Rua Três de Maio 100, 4 andar - Vila Clementino, 04044-020 Lab +55 11 55764438 R.1188 Cell +55 11 92725274 mlima@unifesp.br [[alternative
2008 Dec 11
3
Downloading Reuters data from R
Hi R, Can we download Reuters (3000 Xtra) data from R? Does ODBC package help me in this? Or otherwise, is there a way to extract daily closing prices data of Reuters from R? Thank you very much, Shubha This e-mail may contain confidential and/or privileged i...{{dropped:13}}
2008 Dec 05
1
Cartesian Product Of Character Vectors
Hi all (I'm sure this question has been asked before, but I cant find it). If I have two character vectors: > x <- c("aaa","bbb","ccc") > y <- c("1","2","3") How can I get the cartesian product of the string values? > expand.grid(x,y) Gives me a data frame with separate columns...however, I cant seem to get *apply
2017 Nov 20
2
package check fail on Windows-release only?
I mistakenly left a write in "/tmp" in the rockchalk package (version 1.8.109) that I uploaded last Friday. Kurt H wrote and asked me to fix today. While uploading a new one, I became aware of a problem I had not seen. The version I uploaded last Friday, 1.8.109, has OK status on all platforms except r-release-windows-ix86+x86_64. I get OK on oldrel-windows and also on devel-windows.
2008 Nov 24
4
Calculating sum of letter values
Hi all If I have a string, say "ABCDA", and I want to convert this to the sum of the letter values, e.g. A -> 1 B -> 2 etc, so "ABCDA" = 1+2+3+4+1 = 11 Is there an elegant way to do this? Trying something like which(LETTERS %in% unlist(strsplit("ABCDA", ""))) is not quite correct, as it does not count repeated characters. I guess what I need is
2005 Dec 06
2
Writing a list to a file !
Hi All, This may be trivial in R but I have been trying with out any success. I have a list of 100 elements each having a sub list of different length. I would like to write the list to a ASCII file. I tried with write.table(), after converting my list to a matrix. Now it looks like Robert c("90", "50", "30") John c("91", "20",
2006 Jan 27
3
[Q] extracting lower diagonal elements of a matrix
Hi R users I like to extract lower diagonal elements of a matrix in such a way like, data[1,2], data[1,3], ...., data[5,6] are extracted from a matrix called 'data' This short script below is what I have written so far. ########################################## data <- matrix(rnorm(36,0,1),nrow=6) temp<-c() for (i in 1:(nrow(data)-1)) { for (j in (i+1):nrow(data)) {
2013 Apr 19
3
extracting the diagonal of an inverse matrix
Dear R-users, I would like to know whether there is a way to extract a diagonal of an inverse matrix without computing the inverse of the matrix itself. The size of my matrices are really huge and, also using sparse matrix, computing the inverse leads to storage problems and low speed. In other words, given a square matrix A, I aim to know diag(B), where B=solve(A), without computing solve(A).