user2957945 - 1 year ago 90
R Question

# Print method for multiple matrices

Could someone please suggest a method to

`print`
several matrices side by side in the terminal window.

For the matrices
`m1`
and
`m2`
, I would like the desired output below.

``````m1 <- m2 <- matrix(1:4, nrow=2, dimnames=list(c("a", "b"), c("d", "e")))
``````

Desired output

``````m1      m2
d e     d e
a 1 3   a 1 3
b 2 4   b 2 4
``````

The reason is that I have several 2x2 matrices that i am using in calculations and want to show in a Rmarkdown doc. It takes up a bit too much of the page when printing length ways. Thanks.

EDIT

My attempt at a solution

``````fn <- function(x) setNames(data.frame(.=paste("  ", rownames(x)), x,
check.names=F, row.names=NULL),c(paste(substitute(x)), colnames(x)))
cbind(fn(m1), fn(m2))
#     m1 d e   m2 f g
#1     a 1 3    v 1 3
#2     b 2 4    w 2 4
``````

But this of course doesnt look very good.

A little hack-ish, but I believe it is what you want:

``````m1 <- m2 <- m3 <- m4 <- matrix(1:4, nrow=2, dimnames=list(c("a", "b"), c("d", "e")))
fn <- function(x) setNames(data.frame(.=paste("", rownames(x)), x, check.names=F, row.names=NULL),c(" ", colnames(x)))
matrix.names <- Filter( function(x) 'matrix' %in% class( get(x) ), ls(pattern = "m") )
matrix.list <- lapply(matrix.names, get)
matrix.chain <- do.call(cbind, lapply(matrix.list, fn))
cat(" ", paste0(matrix.names, collapse = "     "), "\n"); print(matrix.chain, row.names = FALSE)
m1     m2     m3     m4
d e    d e    d e    d e
a 1 3  a 1 3  a 1 3  a 1 3
b 2 4  b 2 4  b 2 4  b 2 4
``````
Recommended from our users: Dynamic Network Monitoring from WhatsUp Gold from IPSwitch. Free Download