dfreproject.sip¶

Functions¶

`get_sip_coeffs`(→ Tuple[torch.Tensor, torch.Tensor, ...)	Extract SIP polynomial coefficients from a WCS object.
`apply_sip_distortion`(u, v, sip_coeffs[, device])	Apply SIP distortion to intermediate pixel coordinates.
`apply_inverse_sip_distortion`(u, v, sip_coeffs[, device])	Apply inverse SIP distortion to go from distorted to intermediate coordinates.
`iterative_inverse_sip`(u, v, sip_coeffs[, device, ...])	Iteratively solve for undistorted coordinates when inverse SIP coefficients

Module Contents¶

dfreproject.sip.get_sip_coeffs(wcs: astropy.wcs.WCS) → Tuple[torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor][source]¶

Extract SIP polynomial coefficients from a WCS object.

Parameters:¶

wcsastropy.wcs.WCS: WCS object potentially containing SIP distortion.

Returns:¶

dict:: Dictionary containing SIP coefficient matrices A, B, AP, BP and orders.

dfreproject.sip.apply_sip_distortion(u: torch.Tensor, v: torch.Tensor, sip_coeffs: Tuple, device: str = 'cpu')[source]¶

Apply SIP distortion to intermediate pixel coordinates.

Parameters:¶

u, vtorch.Tensor: Intermediate pixel coordinates (before distortion).
sip_coeffsTuple[torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor]: SIP coefficient matrices.
devicetorch.device, optional: Device to place tensors on.

Returns:¶

tuple:: (u’, v’) distorted coordinates.

# Convert to tensors if needed

dfreproject.sip.apply_inverse_sip_distortion(u: torch.Tensor, v: torch.Tensor, sip_coeffs: Tuple, device: str = 'cpu')[source]¶

Apply inverse SIP distortion to go from distorted to intermediate coordinates.

Parameters:¶

u, vtorch.Tensor: Distorted coordinates.
sip_coeffsTuple: SIP coefficient matrices.
devicetorch.device, optional: Device to place tensors on.

Returns:¶

tuple:: (u’, v’) undistorted coordinates.

dfreproject.sip.iterative_inverse_sip(u: torch.Tensor, v: torch.Tensor, sip_coeffs: Tuple, device: str = 'cpu', max_iter: int = 20, tol: float = 1e-08)[source]¶

Iteratively solve for undistorted coordinates when inverse SIP coefficients are not available.

Parameters:¶

u, vtorch.Tensor: Distorted coordinates.
sip_coeffsTuple: SIP coefficient matrices.
devicetorch.device, optional: Device to place tensors on.
max_iterint, optional: Maximum number of iterations.
tolfloat, optional: Convergence tolerance.

Returns:¶

tuple:: (u’, v’) undistorted coordinates.