逆行列を求めたい

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解説

行列Aの逆行列A^(-1)を求めます。 Matrix?もしくはComplexMatrix?クラスのinverse()メソッドを使うだけです。

サンプルプログラム

inverse.cpp

#include <iostream>
#include <octave/config.h>
#include <octave/CMatrix.h> 

using namespace std;  

int main()
{
  cout.precision(3);
  cout.setf(ios::fixed);
  Complex const IU(0.0, 1.0); 

  int const N = 3; 

  ComplexMatrix A(N, N);
  A(0,0) = 3.0 + IU; A(0,1) = 2.0       ; A(0,2) = IU;     
  A(1,0) = 4.0     ; A(1,1) = 1.0 + IU  ; A(1,2) = 6.0;    
  A(2,0) = 5.0*IU  ; A(2,1) = 3.0 - IU  ; A(2,2) = -4.0*IU;
 
  cout << "originam matrix : A = " << endl << A << endl;
  
  ComplexMatrix A_inv = A.inverse();
  cout << "inverse matrix : A^(-1) = " << endl << A_inv << endl;

  cout << "A A^(-1) = " << endl << A * A_inv << endl;
  cout << "A^(-1) A = " << endl << A_inv * A << endl;
}

出力

originam matrix : A = 
 (3.000,1.000) (2.000,0.000) (0.000,1.000)
 (4.000,0.000) (1.000,1.000) (6.000,0.000)
 (0.000,5.000) (3.000,-1.000) (-0.000,-4.000)

inverse matrix : A^(-1) = 
 (0.061,0.118) (0.094,-0.043) (-0.049,-0.112)
 (0.407,-0.141) (-0.134,-0.043) (0.037,0.165)
 (-0.132,-0.123) (0.119,0.058) (0.054,0.041)

A A^(-1) = 
 (1.000,-0.000) (-0.000,0.000) (-0.000,0.000)
 (-0.000,-0.000) (1.000,0.000) (0.000,0.000)
 (-0.000,0.000) (0.000,0.000) (1.000,-0.000)

A^(-1) A = 
 (1.000,-0.000) (0.000,0.000) (0.000,-0.000)
 (-0.000,0.000) (1.000,0.000) (-0.000,0.000)
 (0.000,0.000) (0.000,-0.000) (1.000,0.000)

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