I think you should reconsider your goal. Matrices must have all elements of the
same type, and in this case you seem to be trying to mix a number of something
(integer) with mean values (double). This would normally be stored together in
a data frame or separately in a vector for counts and a matrix for means.
If you are just thinking about data presentation, a data frame would be a
better choice than a single matrix.
On July 1, 2024 8:54:21 AM PDT, "Sorkin, John" <jsor...@som.umaryland.edu>
wrote:
>#I am trying to write code that will create a matrix with a variable number of
>columns where the #number of columns is 1+Grps
>#I can do this:
>NSims <- 4
>Grps <- 5
>DiffMeans <- matrix(nrow=NSims,ncol=1+Grps)
>DiffMeans
>
>#I have a problem when I try to name the columns of the matrix. I want the
>first column to be NSims, #and the other columns to be something like Value1,
>Value2, . . . Valuen where N=Grps
>
># I wrote a function to build a list of length Grps
>createValuelist <- function(num_elements) {
> for (i in 1:num_elements) {
> cat("Item", i, "\n", sep = "")
> }
>}
>createValuelist(Grps)
>
># When I try to assign column names I receive an error:
>#Error in dimnames(DiffMeans) <- list(NULL, c("NSim", createValuelist(Grps)))
>:
># length of 'dimnames' [2] not equal to array extent
>dimnames(DiffMeans) <- list(NULL,c("NSim",createValuelist(Grps)))
>DiffMeans
>
># Thank you for your help!
>
>
>John David Sorkin M.D., Ph.D.
>Professor of Medicine, University of Maryland School of Medicine;
>Associate Director for Biostatistics and Informatics, Baltimore VA Medical
>Center Geriatrics Research, Education, and Clinical Center;
>PI Biostatistics and Informatics Core, University of Maryland School of
>Medicine Claude D. Pepper Older Americans Independence Center;
>Senior Statistician University of Maryland Center for Vascular Research;
>
>Division of Gerontology and Paliative Care,
>10 North Greene Street
>GRECC (BT/18/GR)
>Baltimore, MD 21201-1524
>Cell phone 443-418-5382
>
>
>
>______________________________________________
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--
Sent from my phone. Please excuse my brevity.
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