similar to: Help wit matrices

Displaying 20 results from an estimated 1000 matches similar to: "Help wit matrices"

2006 Aug 01
4
Overlay Boxplot with scatter plot
I am trying to make a box plot and overlay it with a scatter plot from another data.frame. I was able to successfully create the boxplot, but when i tried using points(x~y...) the dots did not show up. example code aa<-(300,300,300,300,600,600,600,600,900,900,900,900) bb<-(13,12,14,11,56,44,34,75,22.,34,22,98,59,55,56) cc<-(13,12,14,11,56,44,34,75,22.,34,22,98,59,55,56)
2006 Aug 09
3
Unique rows
hello all, I have a dataset where the subjects are duplicated. How do I subset such that I can get only I row/subject. aa<-c(1,1,2,2,3,3,4,4,5,5,6,6) bb<-c(56,56,33,33,53,53,20,20,63,63,9,9) cc<-data.frame(aa,bb) I would like to subset df(cc) such that I can get aa bb 1 56 2 33 3 53 4 20 5 63 6 9 I know this should be fairly easy but I can't figure how to do it in a dataframe and
2006 May 17
1
Example Syntax for if - then- and - else Statements
Hello R users, I am a fairly new R user, however, one of the problems I am having is the use of applying if-, and-, then-, else- statements in R against datasets & dataframe. Rtips mentions it, but without simple examples I am not quite sure what my syntax should look like. I am particularly interested in syntax that can be used with the transform function. for example if foo[,1] ==
2005 Aug 25
4
covariance matrix under null
Hello I am fitting a Cox PH model using the function coxph(). Does anyone know how to obtain the estimate of the covariance matrix under the null hypothesis. The function coxph.detail() does not seem to be useful for this purpose. Thanks, KD. [[alternative HTML version deleted]]
2010 Feb 12
3
Code working but too slow, any idea for how to speed it up ?(no loop in it)
Hello my friends, here is a code I wrote with no loops on matrix that is taking too long (2 seconds and I call him 720 times --> 12 minutes): mat1 and mat2 are both matrix with 103 columns and 164 rows. sequence <- matrix(seq(1 : ncol(mat1))) returns <- apply(sequence, 1, function, mat1= mat1, mat2 = mat2, day = 1) function<- function(mat1, mat2, colNb, day){
2005 Nov 03
4
merging dataframes
Dear List, I often have to merge two or more data frames containing unique row names but with some columns (names) common to the two data frames and some columns not common. This toy example will explain the kind of setup I am talking about: mat1 <- as.data.frame(matrix(rnorm(20), nrow = 5)) mat2 <- as.data.frame(matrix(rnorm(20), nrow = 4)) rownames(mat1) <- paste("site",
2010 Jan 29
7
Simple question on replace a matrix row
Hello, I have a matrix mat1 of dim [1,8] and mat2 of dim[30,8], I want to replace the first row of mat2 with mat1, this is what I do: mat2[1,]<-mat1 but it transforms mat2 in a list I don't understand, I want it to stay a matrix... ----- Anna Lippel -- View this message in context: http://n4.nabble.com/Simple-question-on-replace-a-matrix-row-tp1427857p1427857.html Sent from the R help
2005 Oct 06
1
Compare two distance matrices
Hi all, I am trying to compare two distance matrices with R. I would like to create a XY plot of these matrices and do some linear regression on it. But, I am a bit new to R, so i have a few questions (I searched in the documentation with no success). The first problem is loading a distance matrix into R. This matrix is the output of a the Phylip program Protdist and lookes like this: 5
2007 Nov 12
1
update matrix with subset of it where only row names match
I guess this has a simple solution: I have matrix 'mat1' which has row and column names, e.g.: A B C row1 0 0 0 row2 0 0 0 .... rown 0 0 0 I have a another matrix 'mat2', essentially a subset of 'mat1' where the rownames are all in 'mat1' e.g.: B row3 5 row8 6 row54 7 I want to insert the values of matrix mat2 for column B (in reality it could be some or
2003 Oct 31
2
Summing elements in a list
Hi, Suppose that I have a list where each component is a list of two matrices. I also have a vector of weights. How can I collapse my list of lists into a single list of two matrices where each matrix in the result is the weighted sum of the corresponding matrices. I could use a loop but this is a nested calculation so I was hoping there is a more efficient way to do this. To help clarify,
2007 Nov 21
2
matrix elementwise average with NA's
Hello fellow R users, I have a matrix computation that I imagine should be relatively easy to do, however I cannot figure out a nice way to do it. I have two matrices, for example mat1 <- matrix(c(1:5,rep(NA,5), 6:10), nrow=3, byrow=T) mat2 <- matrix(c(2:6, 6:10, rep(NA,5)), nrow=3, byrow=T) I'd like to compute the element-wise average for non-NA entries. Of course (mat1+mat2)/2
2013 Mar 18
4
Counting confidence intervals
Hi, I have a 2 x 10000 matrix of confidence intervals. The first column is the lower and the next column is the upper. I want to cont how many times a number say 12 lies in the interval. Can anyone assist? -- Thanks, Jim. [[alternative HTML version deleted]]
2007 Apr 20
2
R: Appending the files
Hello R-Experts, I am a beginner to R. Can someone please look at my problem I am trying to append the files in R but couldn't get the answer properly. My code is mat1<-matrix(0,2,3) mat2<-matrix(1,2,3) write.table(mat1,"foo.csv",sep=",",col.names=NA) write.table(mat2,"foo.csv", sep=",", col.names=NA, append = TRUE) I am getting a warning
2007 Jul 24
1
cor inside/outside a function has different output
I'm calculating correlations between two matrices mat1 <- matrix(sample(1:500,25), ncol = 5, dimnames=list(paste("mat1row", 1:5, sep=""), paste("mat1col", 1:5, sep=""))) mat2 <- matrix(sample(501:1000,25), ncol = 5, dimnames=list(paste("mat2row", 1:5, sep=""), paste("mat2col", 1:5, sep="")))
2008 Aug 01
2
Storing Matrices into Hash
Hi, Suppose I have these two matrices (could be more). What I need to do is to store these matrices into a hash. So that I can call back any of the matrix back later. Is there a way to do it? > mat_1 [,1] [,2] [1,] 9.327924e-01 0.067207616 [2,] 9.869321e-01 0.013067929 [3,] 9.892814e-01 0.010718579 [4,] 9.931603e-01 0.006839735 [5,] 9.149056e-01 0.085094444
2010 Mar 29
2
Need help on matrix manipulation
Dear all, Ket say I have 3 matrices : mat1 <- matrix(rnorm(16), 4) mat2 <- matrix(rnorm(16), 4) mat3 <- matrix(rnorm(16), 4) Now I want to merge those three matrices to a single one with dimension 4*3=12 and 4 wherein on resulting matrix, row 1,4,7,10 will be row-1,2,3,4 of "mat1", row 2,5,8,11 will be row-1,2,3,4 of "mat2" and row 3,6,8,12 will be row-1,2,3,4 of
2010 Oct 14
1
rbind ing matrices and resetting column numbers
Sorry for the verbose example. I want to row bind two matrices, and all works except I want the column labelled "row" to be sequential in the new matrix, shown as "mat3" here, i.e. needs to be 1:6 and not 1:3 repeated twice. Any suggestions? Thanks J > colnm1 <- c("row","ti","counti") > colnm2 <-
2013 Jan 04
2
Working with Matrix
Hello again, Let say I have 2 matrices which equal number of columns but different number of rows like: Mat1 <- matrix(1:20, 4, 5) Mat2 <- matrix(1:25, 5, 5) Now for each column 1-to-5 I need to fetch the corresponding columns of these 2 matrices and add the corresponding elements (ignoring NA values if any). Therefore for the 1st column I need to do: (1+1), (2+2),...,(4+4), (NA+5) and
2013 Sep 02
3
Product of certain rows in a matrix
Hi, You could try: A<- matrix(unlist(read.table(text=" 1 2 3 4 5 6 7 8 9 9 8 7 6 5 4 3 2 1 ",sep="",header=FALSE)),ncol=3,byrow=FALSE,dimnames=NULL) library(matrixStats) ?res1<-t(sapply(split(as.data.frame(A),as.numeric(gl(nrow(A),2,6))),colProds)) ?res1 #? [,1] [,2] [,3] #1??? 4?? 10?? 18 #2?? 63?? 64?? 63 #3?? 18?? 10??? 4
2008 Aug 29
2
Newbie: Examples on functions callling a library etc.
Hello R is pretty new to me. I need to write a function that returns three matrices of different dimensions. In addition, I need to call a function from a contributed package with the function. I have browsed several manuals and docs but the examples on them are either very simple or extremely hard to follow. Many thanks Ed [[alternative HTML version deleted]]