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#include <cusp/csr_matrix.h>
#include <cusp/monitor.h>
#include <cusp/krylov/cg.h>
#include <cusp/gallery/poisson.h>
int main(void)
{
// create an empty sparse matrix structure (CSR format)
cusp::csr_matrix<int, float, cusp::device_memory> A;
// initialize matrix
cusp::gallery::poisson5pt(A, 10, 10);
// allocate storage for solution (x) and right hand side (b)
cusp::array1d<float, cusp::device_memory> x(A.num_rows, 0);
cusp::array1d<float, cusp::device_memory> b(A.num_rows, 1);
// set stopping criteria:
// iteration_limit = 100
// relative_tolerance = 1e-6
cusp::default_monitor<float> monitor(b, 100, 1e-6);
// solve the linear system A x = b
cusp::krylov::cg(A, x, b, monitor);
// report solver results
if (monitor.converged())
{
std::cout << "Solver converged to " << monitor.tolerance() << " tolerance";
std::cout << " after " << monitor.iteration_count() << " iterations";
std::cout << " (" << monitor.residual_norm() << " final residual)" << std::endl;
}
else
{
std::cout << "Solver reached iteration limit " << monitor.iteration_limit() << " before converging";
std::cout << " to " << monitor.tolerance() << " tolerance ";
std::cout << " (" << monitor.residual_norm() << " final residual)" << std::endl;
}
return 0;
}
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