Bin size for pdf application
Summary
The bin size when applying the pdf may be a bit too large. Considering that there are about 25
pixels between the camera center and border, we have that the max distance to the camera center is
r_max = 25*size(pixel)
Using the default values for
we obtain for the bin size (considering the interval [r-range, r+range]
subdivided into n
bins):
size(bin) = 2*r*range / 25
The relative size between bins and pixels, when replacing r
by its maximum value r_max
, is therefore:
size(bin) / size(pixel) = (2 * (25 * size(pixel)) * 0.25 / 25) / (size(pixel))
= 0.5
So depending on the star position along the r
axis, the relative bin size with respect to the pixel size can go up to 50%
that may be too large (even considering 25%
at a quarter of the camera).
What is the expected correct behavior?
To be sure there is no precision loss at higher r
(because the total range grows linearly with r
), maybe fixing the bin size and not the number of bins could be useful. The same argument applies to phi
as the total range indirectly grows linearly with r
considering a geometry argument.