Hi there,
I have an adjacency matrix of about 30000x30000 with ~200000 nonzero entries and I would like to use it with MTL. The matrix is in a file in matrix market format and I have slightly modified the first Matrix Insertion example to read it. The insertion of the first 100 elements already takes over 15 sec time, what am I doing wrong? I am using Visual Studio 2008 Express.
The source code is as follows:
// File: insert.cpp
#include <iostream>
#include <boost/numeric/mtl/mtl.hpp>
using namespace mtl;
template <typename Matrix>
void insval(Matrix& m, int index1, int index2, double val)
{
// Matrices are not initialized by default
m= 0.0;
// Create inserter for matrix m
matrix::inserter<Matrix> ins(m);
// Insert value
ins[index1][index2] << val;
}
int main(int argc, char* argv[])
{
compressed2D<double> A(30000, 30000);
FILE* matrixfile;
matrixfile=fopen("A_cpp.txt","r");
int count=0, index1=0, index2=0;
double value=0;
clock_t start, finish;
double duration;
start = clock();
while(fscanf(matrixfile, "%d %d %Lg", &index1, &index2, &value)!=EOF && count<100){// insert first 100 values only
count++;
insval(A, index1-40360, index2-40360, value); // smallest index is 40360...
}
finish = clock();
duration = (double)(finish - start) / CLOCKS_PER_SEC;
printf( "%2.1f seconds\n", duration );
return 0;
}
Thanks for your time!
Rechnan
