JwstDispersionTransform¶

class grizli.grismconf.JwstDispersionTransform(instrument='NIRCAM', module='A', grism='R', conf_file=None, header=None)[source]¶

Rotate NIRISS and NIRCam coordinates such that slitless dispersion has wavelength increasing towards +x. Also works for HST, but does nothing.

Parameters

instrumentstr: Instrument name. E.g., ‘NIRCAM’, ‘NIRISS’, ‘WFC3’.
modulestr: NIRCAM module. Can be ‘A’ or ‘B’.
grismstr: Grism name. Can be ‘R’ or ‘C’ for NIRCAM and ‘GR150R’ or ‘GR150C’ for NIRISS.
conf_filestr: Configuration file to read instrument/grism from. If not provided, will try to infer from the header.
headerastropy.io.fits.Header: Header object to read instrument/grism from. If not provided, will try to infer from the conf_file.

Attributes Summary

`array_center`	Center of rotation
`rot90`	Rotations are all multiples of 90 for now, so compute values that can be passed to `numpy.rot90` for rotating 2D image arrays
`rotation`	Clockwise rotation (degrees) from detector to wavelength increasing towards +x direction
`trace_axis`	Which detector axis corresponds to increasing wavelength

Methods Summary

`forward`(x, y)	Forward transform, detector to +x.
`reverse`(x, y)	Reverse transform, +x to detector.
`rotate_coordinates`(x, y, theta, center)	Rotate cartesian coordinates `x` and `y` by angle `theta` about `center`

Attributes Documentation

array_center¶

Center of rotation

Maybe this is 1020 for NIRISS?

rot90¶: Rotations are all multiples of 90 for now, so compute values that can be passed to numpy.rot90 for rotating 2D image arrays

rotation¶: Clockwise rotation (degrees) from detector to wavelength increasing towards +x direction

Methods Documentation

forward(x, y)[source]¶

Forward transform, detector to +x.

Rotate NIRISS and NIRCam coordinates such that slitless dispersion has wavelength increasing towards +x. Also works for HST, but does nothing.

Parameters

Returns

reverse(x, y)[source]¶

Reverse transform, +x to detector.

Rotates coordinates from the +x direction to the detector frame.

Parameters

Returns

static rotate_coordinates(x, y, theta, center)[source]¶

Rotate cartesian coordinates x and y by angle theta about center

Parameters

Returns