def METHOD_NAME(self, filename):
    """
    Loads a pattern from a tabular pattern file (2 column txt file)
    :param filename: filename of the data file
    """
    logger.info("Load pattern: {0}".format(filename))
    self.pattern_filename = filename
    skiprows = 0
    if filename.endswith('.chi'):
        skiprows = 4
    self.pattern.load(filename, skiprows)
    self.file_name_iterator.update_filename(filename)
    self.pattern_changed.emit()