Is this what you want: > x <- matrix(list(),3,3) # create a matrix of lists > # create matrices for testing > for(i in 1:3){ + for (j in 1:3){ + x[[i,j]] <- matrix(runif((i+1) * (j+1)), i+1) + } + } > > > x [,1] [,2] [,3] [1,] Numeric,4 Numeric,6 Numeric,8 [2,] Numeric,6 Numeric,9 Numeric,12 [3,] Numeric,8 Numeric,12 Numeric,16 > x[[2,2]] # extract one of them [,1] [,2] [,3] [1,] 0.26722067 0.3823880 0.4820801 [2,] 0.38611409 0.8696908 0.5995658 [3,] 0.01339033 0.3403490 0.4935413 > str(x) # structure of the data List of 9 $ : num [1:2, 1:2] 0.266 0.372 0.573 0.908 $ : num [1:3, 1:2] 0.38 0.777 0.935 0.212 0.652 ... $ : num [1:4, 1:2] 0.7894 0.0233 0.4772 0.7323 0.6927 ... $ : num [1:2, 1:3] 0.202 0.898 0.945 0.661 0.629 ... $ : num [1:3, 1:3] 0.2672 0.3861 0.0134 0.3824 0.8697 ... $ : num [1:4, 1:3] 0.2448 0.0707 0.0995 0.3163 0.5186 ... $ : num [1:2, 1:4] 0.206 0.177 0.687 0.384 0.77 ... $ : num [1:3, 1:4] 0.186 0.827 0.668 0.794 0.108 ... $ : num [1:4, 1:4] 0.258 0.4785 0.7663 0.0842 0.8753 ... - attr(*, "dim")= int [1:2] 3 3 >
On Tue, Aug 18, 2009 at 4:48 AM, Michael Kogan<michael.ko...@gmx.net> wrote: > Hi, > > I'm new to programming, new to R and even new to mailing lists so please be > patient with me. I need to manage many matrices generated by an R program. > These matrices have different dimensions and I'd like to group them somehow. > The best way would be to have a big matrix (let's call it database) where > every element database[x,y] consists of a list of matrices that all have the > dimensions ncol(matrix1)=x and nrow(matrix1)=y. So those matrices have to be > embedded into lists and the lists have to be embedded in the big database > matrix. If I simply try > > database=matrix(0,10,10) > database[4,4]=c(matrix1,matrix2) > > I get > > Error in database[4, 4] = c(matrix1, matrix2) : > number of items to replace is not a multiple of replacement length > Execution halted > > which makes sense of course... Is there any possibility to make this work? > Or maybe there is a better way to organize those matrices? > > Regards, > Michael > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve? ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.