Just check the number of search steps needed, it can tell you something more important than time.
Then (I am guessing here), given that your model is based on money it has lost of linear constraints in it, right? There you will only get propagation if by branching either the lower or upper bound of the values for a variable changes. If you just randomize you are likely to choose an inner value which might not give that much propagation. Best Christian -- Christian Schulte, KTH, web.it.kth.se/~cschulte/ -----Original Message----- From: users-boun...@gecode.org [mailto:users-boun...@gecode.org] On Behalf Of negate...@gmail.com Sent: Monday, April 21, 2014 02:47 AM To: users@gecode.org Subject: [gecode-users] Integer Variable Randomization Hi, I'm seeing an exponential time increase in the time to just randomize integer variables. My test program is based on "examples/money.cpp" , and I removed the constraints and simply randomize the integer variables by using INT_VAL_RND() -> branch(*this, le, INT_VAR_SIZE_MIN(), INT_VAL_RND(rnd)); Is the exponential increase in time with the number of integer random variables in Gecode expected ? and if so, why. And can this be improved by modifying the model ? Thanks.. NVars SolveTime(in Seconds) 10000 0.734 20000 3.267 30000 7.67 40000 18.262 50000 31.274 60000 50.674 70000 73.82 Complete Test program - #include <gecode/driver.hh> #include <gecode/int.hh> #include <gecode/minimodel.hh> using namespace Gecode; class Money : public Script { protected: /// Number of letters static const int nl = 70000; // <---- This number corresponds with NVars listed above. /// Array of letters IntVarArray le; public: /// Model variants enum { MODEL_SINGLE, ///< Use single linear equation MODEL_CARRY ///< Use carries }; /// Actual model Money(const Options& opt) : le(*this,nl,0,65535) { // <---------- BOUNDS for integer variable Rnd rnd(314) ; branch(*this, le, INT_VAR_SIZE_MIN(), INT_VAL_RND(rnd)); // <------- Random numbers to integers. } /// Print solution virtual void print(std::ostream& os) const { // os << "\t" << le << std::endl; } /// Constructor for cloning \a s Money(bool share, Money& s) : Script(share,s) { le.update(*this, share, s.le); } /// Copy during cloning virtual Space* copy(bool share) { return new Money(share,*this); } }; /** \brief Main-function * \relates Money */ int main(int argc, char* argv[]) { Options opt("SEND+?MORE=MONEY"); opt.model(Money::MODEL_SINGLE); opt.solutions(1); Script::run<Money,DFS,Options>(opt); std::cout << "--- \n" ; return 0; } // STATISTICS: example-any _______________________________________________ Gecode users mailing list users@gecode.org https://www.gecode.org/mailman/listinfo/gecode-users _______________________________________________ Gecode users mailing list users@gecode.org https://www.gecode.org/mailman/listinfo/gecode-users
