matplotlib/matplotlib · error · RuntimeError

Axis already has an explicit converter set

Error message

Axis already has an explicit converter set

What it means

Error "Axis already has an explicit converter set" thrown in matplotlib/matplotlib.

Source

Thrown at lib/matplotlib/axis.py:2070

        """
        return self._converter

    def set_converter(self, converter):
        """
        Set the unit converter for axis.

        Parameters
        ----------
        converter : `~matplotlib.units.ConversionInterface`
        """
        self._set_converter(converter)
        self._converter_is_explicit = True

    def _set_converter(self, converter):
        if self._converter is converter or self._converter == converter:
            return
        if self._converter_is_explicit:
            raise RuntimeError("Axis already has an explicit converter set")
        elif (
            self._converter is not None and
            not isinstance(converter, type(self._converter)) and
            not isinstance(self._converter, type(converter))
        ):
            _api.warn_external(
                "This axis already has a converter set and "
                "is updating to a potentially incompatible converter"
            )
        self._converter = converter

    def set_units(self, u):
        """
        Set the units for axis.

        Parameters
        ----------
        u : units tag

View on GitHub (pinned to b379c1b69e)

When it happens

Trigger: Thrown at lib/matplotlib/axis.py:2070 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of matplotlib/matplotlib@b379c1b69e (2026-08-21). Data as JSON: /api/errors/edbf7fb8c2ba98dd. Report an issue: GitHub.