Stereographic Projection

Hello, i try to create Stereographic Projection with transformation equations from this link

I have two problems, when the origin of pland have x=0 (i don’t test y=0) i got error
Otherwise the result looks different to their example
The central longitude don’t change anything i keep it 0


Stereographic Projection (16.4 KB)

I remove A0 from A = A0+atan … because in the formula they use A-A0, and i cull the top point but still can’t get the same result like in there example