Hello again Julia users,
Sorry for the noise today, but I have another question which a quick
search didn't answer.
I am working on a function with a loop which creates an enlarged copy
of the same matrix at every iteration. Let's say it looks similar to
this:
for i = 1:N
A = zeros(BigFloat, 2^i, 2^i)
# Now do something with A...
end
I will guess that this is bad performance-wise since Julia needs to
allocate a new array at each iteration through the loop. Also, the GC
needs to come along occasionally and clean up all my old, discarded
arrays. Meanwhile, I have accumulated a large number of old, unused
copies of A. Am I right about the performance problem?
In C I would do something like this:
for(i = 1; i<=N; i++) {
BigFloat* Ar = malloc((2i*2^i)*sizeof(BigFloat));
/* Please forgive the obvious problem with pointers here... */
/* Here I use the array */
free(Ar);
}
That would release the memory at the end of each iteration, and I
could allocate a new Ar at the start of the next iteration.
What's the right way to do this in Julia? Is it OK to invoke a GC run
at the end of each loop, or should I stop worrying and let Julia take
care of memory allocation/deallocation?
Thanks,
Stuart
