An incidence matrix is a matrix A of zeroes and ones. Adding all the ones and zeroes of the lines we get a column vector of the sum of lines, L. Adding all the ones and zeroes of the columns we get a line vector of the sum of columns, C. The operation just described i.e., going from A to L and C, is a trivial one. This program does the opposite, given L and C it calculates one of the incidence matrices.