diff options
| author | Stanislaw Halik <sthalik@misaki.pl> | 2019-03-03 21:09:10 +0100 |
|---|---|---|
| committer | Stanislaw Halik <sthalik@misaki.pl> | 2019-03-03 21:10:13 +0100 |
| commit | f0238cfb6997c4acfc2bd200de7295f3fa36968f (patch) | |
| tree | b215183760e4f615b9c1dabc1f116383b72a1b55 /eigen/doc/special_examples/Tutorial_sparse_example_details.cpp | |
| parent | 543edd372a5193d04b3de9f23c176ab439e51b31 (diff) | |
don't index Eigen
Diffstat (limited to 'eigen/doc/special_examples/Tutorial_sparse_example_details.cpp')
| -rw-r--r-- | eigen/doc/special_examples/Tutorial_sparse_example_details.cpp | 44 |
1 files changed, 0 insertions, 44 deletions
diff --git a/eigen/doc/special_examples/Tutorial_sparse_example_details.cpp b/eigen/doc/special_examples/Tutorial_sparse_example_details.cpp deleted file mode 100644 index bc18b01..0000000 --- a/eigen/doc/special_examples/Tutorial_sparse_example_details.cpp +++ /dev/null @@ -1,44 +0,0 @@ -#include <Eigen/Sparse> -#include <vector> -#include <QImage> - -typedef Eigen::SparseMatrix<double> SpMat; // declares a column-major sparse matrix type of double -typedef Eigen::Triplet<double> T; - -void insertCoefficient(int id, int i, int j, double w, std::vector<T>& coeffs, - Eigen::VectorXd& b, const Eigen::VectorXd& boundary) -{ - int n = int(boundary.size()); - int id1 = i+j*n; - - if(i==-1 || i==n) b(id) -= w * boundary(j); // constrained coefficient - else if(j==-1 || j==n) b(id) -= w * boundary(i); // constrained coefficient - else coeffs.push_back(T(id,id1,w)); // unknown coefficient -} - -void buildProblem(std::vector<T>& coefficients, Eigen::VectorXd& b, int n) -{ - b.setZero(); - Eigen::ArrayXd boundary = Eigen::ArrayXd::LinSpaced(n, 0,M_PI).sin().pow(2); - for(int j=0; j<n; ++j) - { - for(int i=0; i<n; ++i) - { - int id = i+j*n; - insertCoefficient(id, i-1,j, -1, coefficients, b, boundary); - insertCoefficient(id, i+1,j, -1, coefficients, b, boundary); - insertCoefficient(id, i,j-1, -1, coefficients, b, boundary); - insertCoefficient(id, i,j+1, -1, coefficients, b, boundary); - insertCoefficient(id, i,j, 4, coefficients, b, boundary); - } - } -} - -void saveAsBitmap(const Eigen::VectorXd& x, int n, const char* filename) -{ - Eigen::Array<unsigned char,Eigen::Dynamic,Eigen::Dynamic> bits = (x*255).cast<unsigned char>(); - QImage img(bits.data(), n,n,QImage::Format_Indexed8); - img.setColorCount(256); - for(int i=0;i<256;i++) img.setColor(i,qRgb(i,i,i)); - img.save(filename); -} |
