i made the test, here is what i can tell you from my experiments
1) for a mapMatrix ( map<string, map<string, ex> > ) of 8524 x 8524 where all expression where 0, the RAM usage was 6GB ~ 18% of 32GB, very close to your stimation Alexei, you where right on that
2) however, if i repeat the experiment but let the expressions be what they should be (which are pretty large), then RAM usage goes beyond 32GB, i predict is something like 40GB of usage.
3) i would be complaining about the high ammount of RAM usage if it werent because of the following peculiarity. If instead of a mtrix, i decide to store the expresions in a system ecuation form with its corresponding variables (in the way that all elements of a row are grouped into one big polinomial expression), RAM usage is becomes low again!
2) and 3) have the same ammount of terms, just grouped in a different way, it is strange, i am gonna do some more tests and any news i will post back,
Alexei, what is your opinion on my experience?
On Fri, Oct 22, 2010 at 12:34 PM, Cristobal Navarro
<axischire@gmail.com> wrote:
Alexei
thanks for helping,
i am going to do something equivalent to what you suggested, i will fill all expresions of the mapMatrix with zeros, and see how much RAM i consume because of the strings.
ill post my results in a moment.
best regards
Cristobal
On Fri, Oct 22, 2010 at 9:53 AM, Alexei Sheplyakov
<alexei.sheplyakov@gmail.com> wrote:
Hi again,
On Fri, Oct 22, 2010 at 12:22 AM, Cristobal Navarro <
axischire@gmail.com> wrote:
> i kept investigating,
> based on the test i've made, im almost sure, 99%, that the increase in
> memory usage is due to the segmentation of the expressions.
ints (instead of ex*) into that map. Check the memory usage, and compare
it with your calculations.
Use a different data structure (perhaps hash map or a sorted array), and
store ex instead of pointers.
Best regards,
Alexei