[R] overlaying the values of tab-delim file in to a pre-existing matrix

Hello : I have matrix with dimensions(200 X 20,000). I have another file, a tab-delim file where first column variables are row names and second column variables are column names. Tab-delim file has smaller values than the matrix. Matrix = tmat tab-delim file read as data.frame = tb My aim

Re: [R] overlaying the values of tab-delim file in to a pre-existing matrix

Please provide reproducible examples (as discussed at end of each posting): Lines - Apple S 21.0 Apple A 21.6 Apple O 43.0 Orange A 45.0 Orange O 64.0 Orange S 32.5 Mango M 40.3 Mango A 32.6 Mango S 24.6 tb - read.table(textConnection(Lines)) # alternative 1 - create a matrix tmat