Source code for pint.matplotlib

"""
    pint.matplotlib
    ~~~~~~~~~~~~~~~

    Functions and classes related to working with Matplotlib's support
    for plotting with units.

    :copyright: 2017 by Pint Authors, see AUTHORS for more details.
    :license: BSD, see LICENSE for more details.
"""

import matplotlib.units

from .util import iterable, sized


[docs]class PintAxisInfo(matplotlib.units.AxisInfo): """Support default axis and tick labeling and default limits.""" def __init__(self, units): """Set the default label to the pretty-print of the unit.""" super().__init__(label="{:P}".format(units))
[docs]class PintConverter(matplotlib.units.ConversionInterface): """Implement support for pint within matplotlib's unit conversion framework.""" def __init__(self, registry): super().__init__() self._reg = registry
[docs] def convert(self, value, unit, axis): """Convert :`Quantity` instances for matplotlib to use.""" if iterable(value): return [self._convert_value(v, unit, axis) for v in value] else: return self._convert_value(value, unit, axis)
def _convert_value(self, value, unit, axis): """Handle converting using attached unit or falling back to axis units.""" if hasattr(value, "units"): return value.to(unit).magnitude else: return self._reg.Quantity(value, axis.get_units()).to(unit).magnitude
[docs] @staticmethod def axisinfo(unit, axis): """Return axis information for this particular unit.""" return PintAxisInfo(unit)
[docs] @staticmethod def default_units(x, axis): """Get the default unit to use for the given combination of unit and axis.""" if iterable(x) and sized(x): return getattr(x[0], "units", None) return getattr(x, "units", None)
[docs]def setup_matplotlib_handlers(registry, enable): """Set up matplotlib's unit support to handle units from a registry. Parameters ---------- registry : pint.UnitRegistry The registry that will be used. enable : bool Whether support should be enabled or disabled. Returns ------- """ if matplotlib.__version__ < "2.0": raise RuntimeError("Matplotlib >= 2.0 required to work with pint.") if enable: matplotlib.units.registry[registry.Quantity] = PintConverter(registry) else: matplotlib.units.registry.pop(registry.Quantity, None)