def convert_to_ip(self):
if not self.is_data_loaded:<EOL><INDENT>self._import_data()<EOL><DEDENT>if self.is_ip is False:<EOL><INDENT>for coll in self._data:<EOL><INDENT>coll.convert_to_ip()<EOL><DEDENT><DEDENT>self._is_ip = True<EOL>
Convert all Data Collections of this EPW object to IP units.

        This is useful when one knows that all graphics produced from this
        EPW should be in Imperial units.