Error while naming rows and columns of a matrix in R

Question

I have created a matrix in R and. Now I want to name its rows and columns. I have a vector of names and want to assign those names to the rows and columns of my matrix. but it gives me this error: length of 'dimnames' [1] not equal to array extent Here is my code, col is a vector of names.

    cor<-matrix( ,nrow=159,ncol=159)
    index<-2
    for(i in 1:nrow(cor)){

          rownames(cor)[i]<-cols[index]
          index<-index+1

    }

Answer 1

Assuming that cols is a character vector of length 160, then you don't need a loop, you can just do

rownames(cor) <- cols[-1]

or if cols is longer than 160, you can do

rownames(cor) <- cols[2:160]

since you need exactly 159 names for each of the 159 rows in your matrix.