I have problem makin sub-materia (S) from matrix M.
To sub-materia i need to choose colums a,b &c and rows 20-120.
I tried like this, but it didn't work out:
S <- M [M $a & M $ b & M $ c & 20:120,,drop=FALSE $ M]
After that i should do a new sub-materia M1 from recently creates submateria M choosing sekond row.
This should go somelike:
M1 <- M [c(1, 3),]
but i dont know how to make it loop over and over again.