Source code for gammapy.irf.rad_max

# Licensed under a 3-clause BSD style license - see LICENSE.rst
import astropy.units as u
from astropy.visualization import quantity_support
import matplotlib.pyplot as plt
from gammapy.maps.axes import UNIT_STRING_FORMAT
from .core import IRF

__all__ = [
    "RadMax2D",
]


[docs]class RadMax2D(IRF): """2D Rad Max table. This is not directly a IRF component but is needed as additional information for point-like IRF components when an energy or field of view dependent directional cut has been applied. Data format specification: :ref:`gadf:rad_max_2d`. Parameters ---------- energy_axis : `MapAxis` Reconstructed energy axis. offset_axis : `MapAxis` Field of view offset axis. data : `~astropy.units.Quantity` Applied directional cut. meta : dict Metadata dictionary. """ tag = "rad_max_2d" required_axes = ["energy", "offset"] default_unit = u.deg
[docs] @classmethod def from_irf(cls, irf): """Create a RadMax2D instance from another IRF component. This reads the RAD_MAX metadata keyword from the IRF and creates a RadMax2D with a single bin in energy and offset using the ranges from the input IRF. Parameters ---------- irf : `~gammapy.irf.EffectiveAreaTable2D` or `~gammapy.irf.EnergyDispersion2D` IRF instance from which to read the RAD_MAX and limit information. Returns ------- rad_max : `RadMax2D` `RadMax2D` object with a single bin corresponding to the fixed RAD_MAX cut. Notes ----- This assumes the true energy axis limits are also valid for the reconstructed energy limits. """ if not irf.is_pointlike: raise ValueError("RadMax2D.from_irf requires a point-like irf") if "RAD_MAX" not in irf.meta: raise ValueError("Irf does not contain RAD_MAX keyword") rad_max_value = irf.meta["RAD_MAX"] if not isinstance(rad_max_value, float): raise ValueError( f"RAD_MAX must be a float, got '{type(rad_max_value)}' instead" ) energy_axis = irf.axes["energy_true"].copy(name="energy").squash() offset_axis = irf.axes["offset"].squash() return cls( data=rad_max_value, axes=[energy_axis, offset_axis], unit="deg", interp_kwargs={"method": "nearest", "fill_value": None}, )
[docs] def plot_rad_max_vs_energy(self, ax=None, **kwargs): """Plot rad max value against energy. Parameters ---------- ax : `~matplotlib.pyplot.Axes`, optional Matplotlib axes. Default is None. **kwargs : dict Keyword arguments passed to `~matplotlib.pyplot.pcolormesh`. Returns ------- ax : `~matplotlib.pyplot.Axes` Matplotlib axes. """ if ax is None: ax = plt.gca() energy_axis = self.axes["energy"] offset_axis = self.axes["offset"] with quantity_support(): for value in offset_axis.center: rad_max = self.evaluate(offset=value) label = f"Offset {value:.2f}" kwargs.setdefault("label", label) ax.plot(energy_axis.center, rad_max, **kwargs) energy_axis.format_plot_xaxis(ax=ax) ax.set_ylim(0 * u.deg, None) ax.legend(loc="best") ax.set_ylabel(f"Rad max. [{ax.yaxis.units.to_string(UNIT_STRING_FORMAT)}]") return ax
@property def is_fixed_rad_max(self): """Return True if rad_max axes are flat.""" return self.axes.is_flat