While teting gretl I found out that recursive formulas like are very slow when they use a custom defined formula.
The speed is so slow, that it is even faster to program a loop to do the conversion.
I have attached two test program. slow.inp uses a recursive formula and is, as the name says, quite slow. The second script fast.inp calculates the same result but uses a loop.
Is this a bug or should i try to avoid this stuff in my own programs?