MTL decomposed triangular strip matrix line equation

// Solving by Robinkin

#include "mtrix.h" #include "mtl / mtl.h" #include "mtl / utils.h" #include "mtl / tinalg_vec.h"

/ *

X1 = 8;

2 * x1 2 * x2 = 43;

4 * x2 5 * x3 = 86;

6 * x3 7 * x4 = 137

result:

[x1, x2, x3, x4] = [8, 9, 10, 11,]

/ * Sample Output A: [[1,], [2, 3,], [0, 4, 5,], [0, 0, 6, 7,],] B: [8, 43, 86, 137,] A ^ -1 * B: [8, 9, 10, 11,]

* /

Using namespace MTL;

Typedef Matrix , breakd <>, row_major> :: type matrix; // type> vector; type> vector;

INTMAIN () {const INT n = 4;

Matrix a (n, n);

Set_diagonal (a, 1);

// C 1 8 // C A = 2 3 b = 43 // C 4 5 86 // C 6 7 137

A (1, 1) = 3; A (2, 2) = 5; A (3, 3) = 7; A (1, 0) = 2; A (2, 1) = 4; A (3, 2 ) = 6;

Double DB [] = {8, 43, 86, 137}; vector b (db, n);

Std :: Cout << "A:" << std :: endl; print_row (a);

Std :: cout << "B: << std :: endl; print_vector (b);

Tri_solve (a, b);

Std :: cout << "A ^ -1 * b:" << std :: endl;

Print_vector (b);

Return 0;}