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Mathc complexes/01b

Un livre de Wikilivres.

Application

Installer et compiler ce fichier dans votre répertoire de travail.

c00a.c
/* ------------------------------------ */
/*  Save as :   c00a.c                  */
/* ------------------------------------ */
#include "w_a.h"
/* ------------------------------------ */
#define FACTOR_E    +1.E-2         
#define RCA          RC3  
/* ------------------------------------ */       
/* ------------------------------------ */
void fun(void)
{                          
double **A         = i_mZ(RCA,RCA);

double **V         = i_mZ(RCA,RCA);
double **invV      = i_mZ(RCA,RCA);
double **T         = i_mZ(RCA,RCA);

double **EigsValue = i_mZ(RCA,RCA);

   do
  {
   rlower_mZ(A,99);
   eigs_V_mZ(A,V,FACTOR_E);
  }while(!det_Z(V).r||!det_Z(V).i);

  clrscrn();
  printf(" Copy/Past into the octave windows \n\n\n");
  p_Octave_mZ(A,"a",P0,P0);  
  printf(" [V, E]  = eigs (a,%d) \n\n\n",RCA);

  printf(" V :"); 
  pE_mZ(V, S12,P4, S12,P4, C3);
  
  printf(" inv(V) ... Some time the matrix is not invertible :");
  pE_mZ(invgj_mZ(V,invV), S12,P4, S12,P4, C3);
  stop();

  clrscrn(); 
  printf(" A :");
  p_mZ(A, S12,P4, S12,P4, C3);     
 
  printf(" EigsValue = invV * A * V");
  mul_mZ(invV,A,T);
  mul_mZ(T,V,EigsValue);
  p_mZ(clean_eyes_mZ(EigsValue), S12,P4, S8,P4, C3); 
         
  printf(" A = V * EigsValue * invV");
  mul_mZ(V,EigsValue,T);
  mul_mZ(T,invV,A); 
  p_mZ(A, S12,P4, S12,P4, C3);
            
  f_mZ(A);
  f_mZ(V);  
  f_mZ(invV);  
  f_mZ(T);  
  f_mZ(EigsValue);
}
/* ------------------------------------ */
int main(void)
{
time_t t;

  srand(time(&t));

do
{
    fun();
    
} while(stop_w());

  return 0;
}
/* ------------------------------------ */
/* ------------------------------------ */


Valeurs propres vecteurs propres d'une matrice triangulaire inférieur


Remarque :

  • Je n'ai pas les même vecteurs propres que octave.
  • Mais je parviens cependant à calculer les valeurs propres (EigsValue = invV * A * V), et a retrouver la matrice A (A = V * EigsValue * invV).


Exemple de sortie écran :

 Copy/Past into the octave windows 


 a=[
+39+23*i,+0+0*i,+0+0*i;
-84-34*i,+98+54*i,+0+0*i;
-8+24*i,+47-42*i,-88-45*i]

 [V, E]  = eigs (a,3) 


 V :
 -1.2225e-15 +8.0840e-15i  +0.0000e+00 +0.0000e+00i  +2.3075e-01 +5.2479e-01i 
 +3.3067e-01 +8.9918e-01i  +0.0000e+00 +0.0000e+00i  +3.8286e-01 +6.7897e-01i 
 +2.8660e-01 +0.0000e+00i  +1.0000e+00 +0.0000e+00i  +2.5252e-01 +0.0000e+00i 

 inv(V) ... Some time the matrix is not invertible :
 -3.5555e-01 +1.3740e+00i  +3.6026e-01 -9.7964e-01i  +0.0000e+00 +0.0000e+00i 
 -7.5401e-02 +9.4552e-03i  -1.0325e-01 +2.8076e-01i  +1.0000e+00 +0.0000e+00i 
 +7.0212e-01 -1.5968e+00i  -1.1814e-14 +9.0568e-15i  +0.0000e+00 +0.0000e+00i 

 Press return to continue. 


 A :
    +39.0000    +23.0000i      +0.0000     +0.0000i      +0.0000     +0.0000i 
    -84.0000    -34.0000i     +98.0000    +54.0000i      +0.0000     +0.0000i 
     -8.0000    +24.0000i     +47.0000    -42.0000i     -88.0000    -45.0000i 

 EigsValue = invV * A * V
    +98.0000+54.0000i      +0.0000 +0.0000i      +0.0000 +0.0000i 
     +0.0000 +0.0000i     -88.0000-45.0000i      +0.0000 +0.0000i 
     +0.0000 +0.0000i      +0.0000 +0.0000i     +39.0000+23.0000i 

 A = V * EigsValue * invV
    +39.0000    +23.0000i      +0.0000     +0.0000i      +0.0000     +0.0000i 
    -84.0000    -34.0000i     +98.0000    +54.0000i      +0.0000     +0.0000i 
     -8.0000    +24.0000i     +47.0000    -42.0000i     -88.0000    -45.0000i 


 Press   return to continue
 Press X return to stop