The API of the new PhotoCalib object is entirely different from the old Calib API: it is defined in terms of a flux calibration factor instead of a magnitude zero point, methods are named e.g. instFluxToMagnitude instead of getMagnitude, and it never raises an exception when given a negative instrumental flux. To ease the transition to PhotoCalib, I propose that PhotoCalib gain the following deprecated methods from Calib until v18.0:
Other methods on Calib that we will not provide backwards-compatible deprecated methods for:
- setFluxMag0: Invalid; PhotoCalib is immutable.
- getFluxMag0: PhotoCalib has getInstFluxAtZeroMagnitude, which only returns the 0-point and not the 0-point error, which has a non-trivial relationship with the calibration error. This was most commonly used to construct a new Calib, about which see the next point.
- Construction from a "instFlux at zero magnitude" double: this cannot be distinguished from the existing calibrationMean constructor. If such functionality is strongly desired, we could add a makePhotoCalibFromZeroPoint (or similar) free function, but I doubt it is necessary: users rarely have to construct their own photoCalib, and PhotoCalib will be able to read older Exposure files that contain persisted Calibs.
- get/setThrowOnNegativeFlux: Invalid; PhotoCalib is immutable and never throws in this manner.
- operator*= and operator/=: Invalid; PhotoCalib is immutable. We could provide operator* and operator/ though (returning a new PhotoCalib), if this functionality was important.