Initial- and boundary-value problems in Maxima.



On 9/15/2011 3:18 PM, talon at lpthe.jussieu.fr wrote:
...

> This being said the total cost of garbage collection, 2s is negligible 
> with respect to the 60s, but not to the total running time of the 
> fortran version (< 1 s). 

The cost for gc may not be high, but the fact that it is needed at all 
suggests that something is going on that is not necessary.  The fortran 
program presumably just uses the arrays that it is given as arguments, 
so there should be no array allocation.  I think it is just  creating 
floating-point number "boxes".

I don't understand the discrepancy between 50% of the time and 
"negligible" between  Michel and Ray;
since I have some interest (as does Ray) in making lisp numerical 
programs run fast, I hope we can come to some agreement on this.