matplotlib/matplotlib · error · ValueError

Nonstandard magnification in dvi file

Error message

Nonstandard magnification in dvi file

What it means

Error "Nonstandard magnification in dvi file" thrown in matplotlib/matplotlib.

Source

Thrown at lib/matplotlib/dviread.py:558

            vf = _vffile(fontname)
        except FileNotFoundError:
            vf = None
        self.fonts[k] = DviFont(scale=s, metrics=tfm, texname=n, vf=vf)

    @_dispatch(247, state=_dvistate.pre, args=('u1', 'u4', 'u4', 'u4', 'u1'))
    def _pre(self, i, num, den, mag, k):
        self.file.read(k)  # comment in the dvi file
        if i not in [2, 7]:  # 2: pdftex, luatex; 7: xetex
            raise ValueError(f"Unknown dvi format {i}")
        if num != 25400000 or den != 7227 * 2**16:
            raise ValueError("Nonstandard units in dvi file")
            # meaning: TeX always uses those exact values, so it
            # should be enough for us to support those
            # (There are 72.27 pt to an inch so 7227 pt =
            # 7227 * 2**16 sp to 100 in. The numerator is multiplied
            # by 10^5 to get units of 10**-7 meters.)
        if mag != 1000:
            raise ValueError("Nonstandard magnification in dvi file")
            # meaning: LaTeX seems to frown on setting \mag, so
            # I think we can assume this is constant
        self.state = _dvistate.outer

    @_dispatch(248, state=_dvistate.outer)
    def _post(self, _):
        self.state = _dvistate.post_post
        # TODO: actually read the postamble and finale?
        # currently post_post just triggers closing the file

    @_dispatch(249, args=())
    def _post_post(self):
        raise NotImplementedError

    @_dispatch(250, args=())
    def _begin_reflect(self):
        raise NotImplementedError

View on GitHub (pinned to b379c1b69e)

When it happens

Trigger: Thrown at lib/matplotlib/dviread.py:558 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/804d92a06a861346. Report an issue: GitHub.