Set limits for point meta (colormap) for specified subplots.

        :param row_column_list: a list containing (row, column) tuples to
            specify the subplots, or None to indicate *all* subplots.
        :type row_column_list: list or None
        :param min: value for start of the colormap.
        :param max: value for end of the colormap.

def set_mlimits_for_all(self, row_column_list=None, min=None, max=None):
        """Set limits for point meta (colormap) for specified subplots.

        :param row_column_list: a list containing (row, column) tuples to
            specify the subplots, or None to indicate *all* subplots.
        :type row_column_list: list or None
        :param min: value for start of the colormap.
        :param max: value for end of the colormap.

        """
        if row_column_list is None:
            self.limits['mmin'] = min
            self.limits['mmax'] = max
        else:
            for row, column in row_column_list:
                self.set_mlimits(row, column, min, max)