Attachment 537 Details for Bug 949 – Demo

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Demo

eigen_demo.cpp (text/x-csrc), 2.50 KB, created by sebastien.varrette on 2015-02-08 22:04:27 UTC

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Creator: sebastien.varrette

Created: 2015-02-08 22:04:27 UTC

Size: 2.50 KB

patch

obsolete

>#include <iostream>
>#include <string>
>#include <map>
>
>#include <Eigen/Core>
>#include <Eigen/LU>
>
>int main(int argc, char *argv[])
>{
>    Eigen::Matrix<int,3,3> A;
>    A <<
>        -2, 2, -3,
>        -1, 1, 3,
>        2,  0, -1;
>    Eigen::Matrix<int,4,4> B;
>    B <<
>        3,  2,  0,  1,
>        4,  0,  1,  2,
>        3,  0,  2,  1,
>        9,  2,  3,  1;
>    Eigen::Matrix<int,5,5> C0, C1, C2;
>
>    std::map< std::string, int> expected; // All examples checked
>    expected["A"]  = 18; // http://en.wikipedia.org/wiki/Determinant
>    expected["B"]  = 24; // https://people.richland.edu/james/lecture/m116/matrices/determinant.html
>    expected["C0"] = 99; // https://www.physicsforums.com/threads/find-the-determinant-of-a-5-x-5-matrix.146419/
>    expected["C1"] = -25; //
>	expected["C2"] = 0;   // see https://www.youtube.com/watch?v=_JetUVpvFAU
>    C0 <<
>        1, 2, 3, 4, 5,
>        3, 0, 4, 5, 6,
>        2, 1, 2, 3, 4,
>        0, 0, 0, 6, 5,
>        0, 0, 0, 5, 6;
>    C1 <<
>        0, 0,  3, 1, 1,
>        3, 1,  1, 0, 1,
>        1, 0,  2, 3, 3,
>        3, 1,  2, 3, 3,
>        0, 2,  1, 2, 1;
>    C2 <<
>		1, 1,  1,  1,  1,
>		1, 2,  3,  4,  5,
>		1, 3,  6, 10, 15,
>		1, 4, 10, 20, 35,
>		1, 5, 15, 35, 69;
>
>    std::cout << "A = \n" << A << std::endl;
>    std::cout << "[OK] det(A) = " << A.determinant() << " -- expected: " << expected["A"] << std::endl;
>    std::cout << "B = \n" << B << std::endl;
>    std::cout << "[OK] det(B) = " << B.determinant() << " -- expected: " << expected["B"] << std::endl;
>    std::cout << "C0 = \n" << C0 << std::endl;
>    std::cout << "[WRONG] det(C0) = " << C0.determinant() << " -- expected: " << expected["C0"] << std::endl;
>    std::cout << "C1 = \n" << C1 << std::endl;
>    std::cout << "[WRONG] det(C1) = " << C1.determinant() << " -- expected: " << expected["C1"] << std::endl;
>    std::cout << "C2 = \n" << C2 << std::endl;
>    std::cout << "[WRONG] det(C2) = " << C2.determinant() << " -- expected: " << expected["C2"] << std::endl;
>
>    return 0;
>}
>/*
>  Output of the execution of the above program:
>
>  A =
>  -2  2 -3
>  -1  1  3
>  2  0 -1
>  [OK] det(A) = 18 -- expected: 18
>  B =
>  3 2 0 1
>  4 0 1 2
>  3 0 2 1
>  9 2 3 1
>  [OK] det(B) = 24 -- expected: 24
>  C0 =
>  1 2 3 4 5
>  3 0 4 5 6
>  2 1 2 3 4
>  0 0 0 6 5
>  0 0 0 5 6
>  [WRONG] det(C0) = -432 -- expected: 99
>  C1 =
>  0 0 3 1 1
>  3 1 1 0 1
>  1 0 2 3 3
>  3 1 2 3 3
>  0 2 1 2 1
>  [WRONG] det(C1) = -54 -- expected: -25
>  C2 =
>  1  1  1  1  1
>  1  2  3  4  5
>  1  3  6 10 15
>  1  4 10 20 35
>  1  5 15 35 69
>  [WRONG] det(C2) = 1296 -- expected: 0
> */

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