Computing some parts of a function only the first time it is called? For optimization. Dear friends,
This could be a little academic question 🙂
for optimization purposes, would it be possible to compute some precalculations inside a function only the first time it is called? As an example, the attached generalized interpolation function works fine, but to me it is a pity that the vector "vs" get recalculated anytime it is called. To produce the plot, vs will be calculated hundred of times, all the times identical. Let say that I "know" that vx and vy will remain the same.
I am perfectly aware that I could compute vs "outside" the function, making it a "global variable". But I would like to incapsulate this in the function itself. In good old times 🙂 of FORTRAN programming, there was, I believe to remember, a trick based on a DATA statement that preloaded a variable at compile time. At the first execution of a subroutine one could check if the value was the preloaded one, the subroutine knew it was being
