RotatedFrameFitter¶

class trackstream.preprocess.RotatedFrameFitter(data: astropy.coordinates.BaseCoordinateFrame, origin: astropy.coordinates.builtin_frames.ICRS, **kwargs)[source]¶

Bases: object

Class to Fit Rotated Frames.

Todo

include errors.

Parameters

dataBaseCoordinateFrame: In ICRS coordinates.
originICRS: location of point on sky about which to rotate.

Other Parameters

rot_lower, rot_upperQuantity, (optional, keyword-only): The lower and upper bounds in degrees. Default is (-180, 180] degree.
origin_limQuantity, (optional, keyword-only): The symmetric lower and upper bounds on origin in degrees. Default is 0.005 degree.
fix_originbool (optional, keyword-only): Whether to fix the origin point. Default is False.
use_lmfitbool or None, (optional, keyword-only): Whether to use lmfit package. None (default) falls back to config file.
leastsquaresbool (optional, keyword-only): If use_lmfit is False, whether to to use least_square() or minimize() Default is False
align_vbool: Whether to align by the velocity.

Attributes Summary

default_fit_options

Methods Summary

`align_v_positive_lon`(fit_values[, subsel])	Align the velocity along the positive Longitudinal direction.
`fit`([rot0, bounds, fix_origin, use_lmfit, ...])	Find Best-Fit Rotated Frame.
`plot_data`()
`plot_residual`([fitresult, num_rots, scalar])	Plot Residual as a function of rotation angle.
`residual`(rotation, *[, scalar])	How close phi2, the rotated latitude (dec), is to flat.
`set_bounds`([rot_lower, rot_upper, origin_lim])	Make bounds on Rotation parameter.

Attributes Documentation

default_fit_options¶

Methods Documentation

align_v_positive_lon(fit_values: Dict[str, Any], subsel: Union[ellipsis, Sequence, slice] = Ellipsis)[source]¶

Align the velocity along the positive Longitudinal direction.

Parameters

fit_valuesdict: The rotation and origin. Output of minimize
subselslice: sub-select a portion of the pm_lon_coslat for determining the average velocity.

Returns

valuesdict: fit_values with “rotation” adjusted.

fit(rot0: Optional[astropy.units.quantity.Quantity] = None, bounds: Optional[Sequence] = None, *, fix_origin: Optional[bool] = None, use_lmfit: Optional[bool] = None, leastsquares: Optional[bool] = None, align_v: Optional[bool] = None, **kwargs)[source]¶

Find Best-Fit Rotated Frame.

Parameters

rot0Quantity, optional

Initial guess for rotation

boundsarray-like, optional

Parameter bounds.

[[rot_low, rot_up],
 [lon_low, lon_up],
 [lat_low, lat_up]]

Returns

resAny: The result of the minimization. Depends on arguments.
Dict[str, Any]: Has fields “rotation” and “origin”.

Other Parameters

fix_originbool (optional, keyword-only): Whether to fix the origin.
use_lmfitbool (optional, keyword-only): Whether to use lmfit package
leastsquaresbool (optional, keyword-only): If use_lmfit is False, whether to to use least_square() or minimize() (default)
align_vbool (optional, keyword-only): Whether to align velocity to be in positive direction
fit_kwargs:: Into whatever minimization package / function is used.

Raises

ImportError: If use_lmfit and lmfit is not installed.

plot_data()[source]¶

plot_residual(fitresult=None, num_rots: int = 3600, scalar: bool = True)[source]¶: Plot Residual as a function of rotation angle.

residual(rotation, *, scalar: bool = False)[source]¶

How close phi2, the rotated latitude (dec), is to flat.

Parameters

rotationfloat: The final rotation of the frame about the origin. The sign of the rotation is the left-hand rule. That is, an object at a particular position angle in the un-rotated system will be sent to the positive latitude (z) direction in the final frame. In degrees.

Returns

resfloat or Sequence: \(\rm{lat} - 0\). If scalar is True, then sum array_like to return float.

Other Parameters

scalarbool (optional, keyword-only): Whether to sum res into a float. Note that if res is also a float, it is unaffected.

set_bounds(rot_lower: astropy.units.quantity.Quantity = <Quantity -180. deg>, rot_upper: astropy.units.quantity.Quantity = <Quantity 180. deg>, origin_lim: astropy.units.quantity.Quantity = <Quantity 0.005 deg>) → Tuple[float, float][source]¶

Make bounds on Rotation parameter.

Parameters

rot_lower, rot_upperQuantity, optional: The lower and upper bounds in degrees.
origin_limQuantity, optional: The symmetric lower and upper bounds on origin in degrees.

Navigation

RotatedFrameFitter¶