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, sep=',', noquote=True)
    output = [['Locus', 'Group', 'Position']]
    for row in matrix:
        if row[0] and not re.match(r'c\d+\.loc[\d\.]+', row[0]):
            output.append([row[0], row[1], row[2]])
    return output