superphot_pipeline.astrometry.transformation module¶
Class Inheritance Diagram¶
Define a class to apply sky-to-frame transformations.
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class
superphot_pipeline.astrometry.transformation.Transformation(trans_fname=None)[source]¶ Bases:
object
A clas that applies transformations generated by anmatch.
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__call__(sources, save_intermediate=False)[source]¶ Return the x and y coordinates to which the given (ra, dec) project to.
Parameters: - sources – The sky position to project to frame coordinates. Should have keys named ‘RA’ and ‘Dec’ in degrees.
- save_intermediate – Should the intermediate coordinates be saved. Those are the coordinates after apllying the sky projection and before applying the polynomial transformation.
Returns: - The position in pixels relative to the lower left
frame of the corner to which the given sky position projects under the currently defined transformation, as a numpy array with fields named ‘x’ and ‘y’. If save_intermediate is True, the result also contains fields called ‘xi’ and ‘eta’ containing the intermediate coordinates.
Return type: projected
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evaluate_polynomial(projected, transformed)[source]¶ Apply the currently defined polynomial transfomation to (xi, eta).
Parameters: - projected – The projected (c.f. gnomonic_projection()) coordinates to transform. Should have ‘xi’ and ‘eta’ keys containing the projected coordinates to transform in degrees.
- transformed – A numpy array with ‘x’ and ‘y’ fields to fill with the transformed coordinates (in pixels).
Returns: None
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gnomonic_projection(sources, projected)[source]¶ Project the given sky position to a tangent plane (gnomonic projection).
Parameters: - sources – The the sky position to project (should have ‘RA’ and ‘Dec’ keys coordinates in degrees.
- projected – A numpy array with ‘xi’ and ‘eta’ fields to fill with the projected coordinates (in degrees).
Returns: None
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