Return the matrix representation of the genetic map.

    :arg inputfile: the path to the input file from which to retrieve the
        genetic map.

def get_map_matrix(inputfile):
    """ Return the matrix representation of the genetic map.

    :arg inputfile: the path to the input file from which to retrieve the
        genetic map.

    """
    matrix = read_input_file(inputfile)
    output = []
    for row in matrix:
        if row[3]:
            output.append([row[3], row[1], row[2]])
    return output