C99 VLA are not dynamically allocated, they exhaust the static stack rather
quickly. If you are writing the C part of the code yourself it is in the
long run almost certainly better to put matrices on the heap. If you have a
maximal size for arrays you could use that as static bound. Or replace them
with a C++ matrix class that does the dynamic allocation (e.g.
boost::numeric::ublas::matrix)
On Thursday, October 16, 2014 12:28:21 PM UTC+1, Dima Pasechnik wrote:
>
> In C99 it's possible to do dynamic allocation of multidimensional arrays:
>
> void blah(int n) {
> int a[n][n];
> ...}
>
> but this does not seem to be supported in Cython. If I try
> sage -cython on
>
> def t(int n):
> cdef int a[n][n]
> cdef int i, j
> for i in range(n):
> for j in range(n):
> a[i][j]=i+j
> return a[0][n-1]
>
> I get
>
> Error compiling Cython file:
> ------------------------------------------------------------
> ...
> def t(int n):
> cdef int i, j
> cdef int a[n][n]
> ^
> ------------------------------------------------------------
>
> m.pyx:3:18: Not allowed in a constant expression
>
> As I have C99 code I'd like to hook up to Sage, I'd really
> like to know how to get around this limitation (with as little overhead
> as possible)
>
> Thanks,
> Dima
>
>
>
--
You received this message because you are subscribed to the Google Groups
"sage-devel" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sage-devel.
For more options, visit https://groups.google.com/d/optout.
