import numpy as np
import traitlets as traits
from ctapipe.containers import MuonRingContainer
from ctapipe.core import Component
from .fitting import kundu_chaudhuri_circle_fit, taubin_circle_fit
# the fit methods do not expose the same interface, so we
# force the same interface onto them, here.
# we also modify their names slightly, since the names are
# exposed to the user via the string traitlet `fit_method`
def kundu_chaudhuri(fov_lon, fov_lat, weights, mask):
"""kundu_chaudhuri_circle_fit with fov_lon, fov_lat, weights, mask interface"""
return kundu_chaudhuri_circle_fit(fov_lon[mask], fov_lat[mask], weights[mask])
def taubin(fov_lon, fov_lat, weights, mask):
"""taubin_circle_fit with fov_lon, fov_lat, weights, mask interface"""
return taubin_circle_fit(fov_lon, fov_lat, mask)
[docs]
def kundu_chaudhuri_taubin(fov_lon, fov_lat, weights, mask):
"""taubin_circle_fit with fov_lon, fov_lat, weights, mask interface
with initial parameters provided by kundu_chaudhuri"""
taubin_r_initial, xc_initial, yc_initial, _, _, _ = kundu_chaudhuri_circle_fit(
fov_lon[mask], fov_lat[mask], weights[mask], nan_errors_flag=True
)
return taubin_circle_fit(
fov_lon,
fov_lat,
mask,
weights,
taubin_r_initial,
xc_initial,
yc_initial,
)
FIT_METHOD_BY_NAME = {
m.__name__: m for m in [kundu_chaudhuri, taubin, kundu_chaudhuri_taubin]
}
__all__ = ["MuonRingFitter"]
[docs]
class MuonRingFitter(Component):
"""Different ring fit algorithms for muon rings"""
fit_method = traits.CaselessStrEnum(
list(FIT_METHOD_BY_NAME.keys()),
default_value="kundu_chaudhuri_taubin",
).tag(config=True)
[docs]
def __call__(self, geom, image, clean_mask):
"""
Perform a circle fit to ``image`` with the chosen ``fit_method``.
Parameters
----------
geom: CameraGeometry
Defines the pixel coordinates.
Must be in the `ctapipe.coordinates.TelescopeFrame`
image: np.ndarray[np.float32]
Image intensity values
clean_mask: np.array([],dtype=bool)
Boolean mask of clean pixels, where True means the pixel contains signal.
This can be generated using a `ctapipe.image.ImageCleaner`.
Returns
-------
MuonRingContainer:
Results of the ring fit.
"""
fit_function = FIT_METHOD_BY_NAME[self.fit_method]
(
radius,
center_fov_lon,
center_fov_lat,
radius_err,
center_fov_lon_err,
center_fov_lat_err,
) = fit_function(geom.pix_x, geom.pix_y, image, clean_mask)
return MuonRingContainer(
center_fov_lon=center_fov_lon,
center_fov_lat=center_fov_lat,
radius=radius,
center_fov_lon_err=center_fov_lon_err,
center_fov_lat_err=center_fov_lat_err,
radius_err=radius_err,
center_phi=np.arctan2(center_fov_lat, center_fov_lon),
center_distance=np.sqrt(center_fov_lon**2 + center_fov_lat**2),
)
