# PYME.localization.FitFactories.zEstimators.priEstimator module¶

Calculates starting parameters for fitting to a phase ramp PSF. As it uses the angle between the lobes it should also be able to be used for double helix PSFs with little/no modification

PYME.localization.FitFactories.zEstimators.priEstimator.calibrate(interpolator, md, roiSize=5)
PYME.localization.FitFactories.zEstimators.priEstimator.getStartParameters(data, X, Y, Z=None)