def load_umatrix(self, filename):
        """Load the umatrix from a file to the Somoclu object.

        :param filename: The name of the file.
        :type filename: str.
        """

        self.umatrix = np.loadtxt(filename, comments='%')
        if self.umatrix.shape != (self._n_rows, self._n_columns):
            raise Exception("The dimensions of the U-matrix do not "
                            "match that of the map")
Load the umatrix from a file to the Somoclu object.

        :param filename: The name of the file.
        :type filename: str.