From: Markus Weimer (markus.weimer_at_[hidden])
Date: 2007-07-04 21:14:17
Hi,
thanks for all the answers. As you might have guessed by now, Choon and me
are working on the same project. I was away so he took over this thread ;-)
Take care,
Markus
On 6/30/07, Gunter Winkler <guwi17_at_[hidden]> wrote:
>
> Am Freitag, 29. Juni 2007 12:53 schrieb Markus Weimer:
> > This version often is 10-20 times faster than the prod in uBLAS on
> > sparse M. While this is all good, the implementation in test_fast()
> > in the attached source is sometimes 1000 times faster on very sparse
> > matrices, for example when running the code with the following
> > parameters:
>
> --------------------------
> ublas compressed_matrix
> --------------------------
> M: 100000x10000
> rightmult time : 0.0100
> our ublas leftmult time : 30.5100
> ublas leftmult time : 0.0200
> rightmult 1-norm : 1001294.00000000
> ublas leftmult 1-norm : 1001294.00000000
> our ublas leftmult 1-norm : 1001294.00000000
>
> uBLAS is quite fast here ;-)
>
> ---8<---
> #include <boost/numeric/ublas/operation.hpp>
> //...
> template <class MType>
> void test_ublas(const size_t row, const size_t col, const char* data,
> const unsigned int maxloop){
> MType X(row,col);
> fill_ublas(row, col, data, X);
> vector<double> w(X.size2());
> for(size_t i=0; i<w.size(); ++i) w(i) = 1.0;
>
>
> vector<double> result(X.size1());
>
> const clock_t rightMultStartTime = clock();
> for(unsigned int loop=0; loop<maxloop; loop++) {
> // result = prod(X, w);
> axpy_prod(X, w, result, true);
> }
> const clock_t rightMultEndTime = clock();
> const double rm_1norm = norm_1(result);
>
> vector<double> l(row);
> for(size_t i=0; i<l.size(); ++i){
> l[i] = 1.0;
> }
>
> vector<double> ourGrad(X.size2());
>
> const clock_t leftMultStartTime = clock();
> for(unsigned int i=0; i<maxloop; i++) {
> ourGrad = ourProd<vector<double>, MType, vector<double> >(l,X);
> }
> const clock_t leftMultEndTime = clock();
> const double our_l1norm = norm_1(ourGrad);
> assert(l.size() == row);
> assert(ourGrad.size() == col);
> assert(X.size1() == row);
> assert(X.size2() == col);
>
>
>
> vector<double> uBLASGrad(X.size2());
> const clock_t uBlasLeftMultStart = clock();
> for(unsigned int i=0; i<maxloop; i++) {
> // uBLASGrad = prod(l, X);
> axpy_prod(trans(X), l, uBLASGrad, true);
> }
>
> const clock_t uBlasLeftMultStop = clock();
> const double ublas_l1norm = norm_1(uBLASGrad);
>
> const double ublasleftTime = ((double)(uBlasLeftMultStop -
> uBlasLeftMultStart))/CLOCKS_PER_SEC;
> const double leftTime = ((double)(leftMultEndTime -
> leftMultStartTime))/CLOCKS_PER_SEC;
> const double rightTime = ((double)(rightMultEndTime -
> rightMultStartTime))/CLOCKS_PER_SEC;
>
> // display time elapsed
> printf("rightmult time : %.4lf\n",rightTime);
> printf("our ublas leftmult time : %.4lf\n",leftTime);
> printf("ublas leftmult time : %.4lf\n",ublasleftTime);
> printf("rightmult 1-norm : %.8lf\n",rm_1norm);
> printf("ublas leftmult 1-norm : %.8lf\n",ublas_l1norm);
> printf("our ublas leftmult 1-norm : %.8lf\n",our_l1norm);
> }
>
>
> --->8----
>
>
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>
>
>