astropy:docs

SIP

class astropy.modeling.polynomial.SIP(crpix, a_order, a_coeff, b_order, b_coeff, ap_order=None, ap_coeff=None, bp_order=None, bp_coeff=None, param_dim=1)[source] [edit on github]

Bases: astropy.modeling.core.Model

Simple Imaging Polynomial (SIP) model.

The SIP convention is used to represent distortions in FITS image headers. See [R5] for a description of the SIP convention.

Parameters :

crpix : list or ndarray of length(2)

CRPIX values

a_order : int

SIP polynomial order for first axis

a_coeff : dict

SIP coefficients for first axis

coeff_prefix : str: ‘a’, ‘b’, ‘A’ or ‘B’

SIP coefficient preffix

b_order : int

SIP order for second axis

b_coeff : dict

SIP coefficients for the second axis

a_inv_order : int

order for the inverse transformation (AP coefficients)

a_inv_coeff : dict

coefficients for the inverse transform

b_inv_order : int

order for the inverse transformation (BP coefficients)

b_inv_coeff : dict

coefficients for the inverse transform

param_dim : int

number of parameter sets

References

[R5](1, 2) David Shupe, et al, ADASS, ASP Conference Series, Vol. 347, 2005

Attributes Summary

n_inputs int(x=0) -> int or long
n_outputs int(x=0) -> int or long

Methods Summary

inverse()

Attributes Documentation

n_inputs = 2
n_outputs = 2

Methods Documentation

inverse()[source] [edit on github]

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