Yes, that is correct the values are a function of cos(theta) (x-axis) and r (y-axis). ‘cos(theta)’ and ‘r’ are the indices of the array. The values that you mention （-5.3374109887996959E-287）don’t sound unreasonable since for ‘r > 16’ the function effectively goes to zero.
The reading should be straight forward, but if I start from this solution what changes do I have to make to it to read the data in C?