Re: Computer Algebra Algorithms lisp vs. C.

I don't understand why you speak of optimisation, if you have
for some reason to manipulate multivariate polynomials,
there is no way to avoid large data. Parsing and printing
them each time you call a CAS function with a string interface
would therefore cost (too) much time.



You are advocating that marshalling be optimised away. I am saying that this
is a premature optimisation because you haven't gathered data on the time
taken to marshal compared to the time taken to do any symbolic
computations.


Sorry, I'm not a native English speaker, I don't understand what
you mean by marshalling.
My point is that if for some reason you have to manipulate large
data (multivariate polynomials being one example), you will loose
too much time if you have to parse/print for every operation. And
you can easily get large data even if you
have small data in input, think of Groebner basis computation
for example, or to the division of say x^1000-1 by x-1.

I'll time it properly when I find the time. My guess would be that the
performance of operations which are equivalently implemented in C++ in your
code will be less than a factor of 2 slower in my code and the performance
of operations not implemented in C++ in your code will be 2-3 orders of
magnitude faster in my implementation.


All the operations available to the user are implemented in C++ in my
code. There is no kernel/user language approach. That's why everything
is directly available to the C++ programmer.
.