SIP#

class astropy.modeling.polynomial.SIP(crpix, a_order, b_order, a_coeff={}, b_coeff={}, ap_order=None, bp_order=None, ap_coeff={}, bp_coeff={}, n_models=None, model_set_axis=None, name=None, meta=None)[source]#

Bases: Model

Simple Imaging Polynomial (SIP) model.

The SIP convention is used to represent distortions in FITS image headers. See [1] for a description of the SIP convention.

Parameters:

crpixpython:list or (2,) ndarray: CRPIX values
a_orderpython:int: SIP polynomial order for first axis
b_orderpython:int: SIP order for second axis
a_coeffpython:dict: SIP coefficients for first axis
b_coeffpython:dict: SIP coefficients for the second axis
ap_orderpython:int: order for the inverse transformation (AP coefficients)
bp_orderpython:int: order for the inverse transformation (BP coefficients)
ap_coeffpython:dict: coefficients for the inverse transform
bp_coeffpython:dict: coefficients for the inverse transform

References

[1]

David Shupe, et al, ADASS, ASP Conference Series, Vol. 347, 2005

Attributes Summary

`n_inputs`
`n_outputs`

Methods Summary

`__call__`	Evaluate this model using the given input(s) and the parameter values that were specified when the model was instantiated.
`evaluate`(x, y)	Evaluate the model on some input variables.

Attributes Documentation

n_inputs = 2#

n_outputs = 2#

Methods Documentation

__call__()#: Evaluate this model using the given input(s) and the parameter values that were specified when the model was instantiated.

evaluate(x, y)[source]#: Evaluate the model on some input variables.