## -----------------------------------------------------------------------------
library(diagonals)
fatdiag(12, steps=3)

## -----------------------------------------------------------------------------
( m <- matrix(111, nrow=6, ncol=9) )
fatdiag(m, steps=3) <- 5
m

## -----------------------------------------------------------------------------
fatdiag(m, steps=3)

## -----------------------------------------------------------------------------
fatdiag(12, size=4)

## -----------------------------------------------------------------------------
fatdiag(12, size=c(3,4) )