fit_diffraction_spike¶

psfsubtraction.prepare.
fit_diffraction_spike
(image, fac=1, r_inner=50, r_outer=250, width=25, initial_guess=<function center_of_mass>)[source] [edit on github]¶ fit a diffraction spike with a line
Regions with low signal, i.e. regions where the maximum is not well determined (standard deviation < 40% percentile indicates that all pixels in that strip are very similar, meaning that these pixels contain mostly sky and not signal).
Parameters:  image : np.array
2 dimensional image
 fac : float
Initial guess for the parameter m in the equation y = m*x+b.
 r_inner, r_outer : float
The fit is done on the left side of the image from
r_outer
tor_inner
and on the right side from+r_inner
to+r_outer
(all coordinates in pixels, measured from the center of the image). Use these parameters to contrain the fit to a region with a strong, but not saturated signal. width : float
For each column in the image, a
width
strip of pixels centered on the initial guess is extracted and the position of the maximum is recorded. initial guess : tuple or callable
This can either be a numeric value for an initial guess such as
(54, 67.7)
for a function that accepts and 2 d array (the image) and returns an tuple.
Returns:  m, b : float
coefficients for a line of the form y = m x + b