Manually specify the x-axis log tick values.

        :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 logticks: logarithm of the locations for the ticks along the
            axis.

        For example, if you specify [1, 2, 3], ticks will be placed at 10,
        100 and 1000.

def set_logxticks_for_all(self, row_column_list=None, logticks=None):
        """Manually specify the x-axis log tick values.

        :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 logticks: logarithm of the locations for the ticks along the
            axis.

        For example, if you specify [1, 2, 3], ticks will be placed at 10,
        100 and 1000.

        """
        if row_column_list is None:
            self.ticks['x'] = ['1e%d' % u for u in logticks]
        else:
            for row, column in row_column_list:
                self.set_logxticks(row, column, logticks)