JavaScript Matrix Function

I need a javascript function written that can create a matrix of the kind needed to work with d3.chords. My source is a CSV file that has rows and columns but that is not in a square matrix. The function ought to take the CSV file and create duplicated rows and columns and fill the respective values. The column and row names may be long strings with funny characters. Eg. source A B C D Y 0 0 0 0 T 1 1 1 1 Z 0 0 0 0 X 1 1 1 1 becomes A B C D Y T Z X Y T Z X A B C D (with the values completed automatically).