XYAxes.dualx(transform, transform_kw=None, **kwargs)[source]

Makes a secondary x axis for denoting equivalent x coordinates in alternate units.

  • forward (function, optional) – Function used to transform units from the original axis to the secondary axis. Should take 1 value and perform a forward linear transformation. For example, to convert Kelvin to Celsius, use ax.dualx(lambda x: x - 273.15). To convert kilometers to meters, use ax.dualx(lambda x: x*1e3).

  • inverse (function, optional) – Function used to transform units from the secondary axis back to the original axis. If forward was a non-linear function, you must provide this, or the transformation will be incorrect!

    For example, to apply the square, use ax.dualx(lambda x: x**2, lambda x: x**0.5).

  • scale (scale-spec, optional) – The axis scale from which forward and inverse transformations are inferred. Passed to Scale.

    For example, to apply the inverse, use ax.dualx('inverse'); To apply the base-10 exponential function, use ax.dualx(('exp', 10, 1, 10)) or ax.dualx(plot.Scale('exp', 10)).

  • scale_kw (dict-like, optional) – Ignored if scale is None. Passed to Scale.

  • label, locator, formatter, ticks, ticklabels, minorlocator, minorticks, tickminor, ticklen, tickrange, tickdir, ticklabeldir, tickrotation, bounds, margin, color, grid, gridminor, gridcolor (optional) – Prepended with 'y' and passed to Axes.format.