Mathc matrices/c24o
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c02d.c |
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/* ------------------------------------ */
/* Save as : c02d.c */
/* ------------------------------------ */
#include "v_a.h"
/* ------------------------------------ */
/* ------------------------------------ */
#define RA R2
#define CA C2
#define RX R2
#define CX C1
/* ------------------------------------ */
/* ------------------------------------ */
int main(void)
{
double a[RA*CA]={
+3, -2,
+2, -2
};
double x_B[RX*CX]={
+1,
+2
};
double b[RA*CA]={
+2, +4,
+3, +5
};
double **A = ca_A_mR(a, i_mR(RA,CA));
double **B = ca_A_mR(b, i_mR(RA,CA));
double **D = i_mR(RA,CA) ;
double **X_B = ca_A_mR(x_B, i_mR(RX,CX));
double **X = mul_mR(B,X_B, i_mR(RX,CX));
double **T = i_mR(RA,CX) ;
double **invB = inv_mR(B, i_mR(RA,CA));
double **invBA = i_mR(RA,CA) ;
double **DX_B = i_mR(RA,CX) ;
/* D = invB*A*B */
mul_mR(invB,A,invBA);
mul_mR(invBA,B,D);
/* [T(x)]_B = D*x_B */
mul_mR(D,X_B,DX_B);
clrscrn();
printf(" In the Standard basis\n\n"
" T(x) = A*x");
p_mR(mul_mR(A,X,T),S4,P2,C7);
printf(" In the the B basis with D = invB*A*B\n\n"
" [T(x)]_B = D*x_B");
p_mR(DX_B,S4,P2,C7);
printf(" Verify the result if it is the same in the two basis :\n\n"
" With B*[x_B] = [x] then B*[D*x_B] = [A*x]\n\n"
" B*[D*x_B]");
p_mR(mul_mR(B,DX_B,T),S4,P2,C7);
stop();
f_mR(A);
f_mR(B);
f_mR(D);
f_mR(X_B);
f_mR(X);
f_mR(T);
f_mR(invB);
f_mR(invBA);
f_mR(DX_B);
return 0;
}
/* ------------------------------------ */
/* ------------------------------------ */
Vérifions si les résultats sont compatibles
Exemple de sortie écran :
------------------------------------
In the Standard basis
T(x) = A*x
+4.00
-6.00
In the the B basis with D = invB*A*B
[T(x)]_B = D*x_B
-22.00
+12.00
Verify the result if it is the same in the two basis :
With B*[x_B] = [x] then B*[D*x_B] = [A*x]
B*[D*x_B]
+4.00
-6.00
Press return to continue.