Linear Algebra and the C Language/a03p
Install and compile this file in your working directory.
/* ------------------------------------ */
/* ------------------------------------ */
/* Save as : c01e.c */
/* ------------------------------------ */
#include "v_a.h"
/* ------------------------------------ */
#define RA R5
#define CA C3
/* ------------------------------------ */
#define FACTOR_E +1.E-0
/* ------------------------------------ */
void fun(void)
{
double **A = r_mR(i_mR(RA,CA),9);
double **Pinv = i_mR(CA,RA);
double **PinvA = i_mR(CA,CA);
double **PinvAPinv = i_mR(CA,RA);
clrscrn();
printf(" A :");
p_mR(A,S7,P2,C7);
printf(" Pinv = V * invS_T * U_T ");
Pinv_Rn_mR(A,Pinv,FACTOR_E);
pE_mR(Pinv,S12,P4,C10);
stop();
clrscrn();
printf(" Pinv*A :");
mul_mR(Pinv,A,PinvA);
p_mR(PinvA,S7,P2,C10);
printf(" Pinv*A*Pinv :");
mul_mR(PinvA,Pinv,PinvAPinv);
p_mR(PinvAPinv,S7,P4,C10);
printf(" Pinv :");
p_mR(Pinv,S7,P4,C7);
f_mR(A);
f_mR(Pinv);
f_mR(PinvA);
f_mR(PinvAPinv);
}
/* ------------------------------------ */
int main(void)
{
time_t t;
srand(time(&t));
do
{
fun();
} while(stop_w());
return 0;
}
/* ------------------------------------ */
/* ------------------------------------ */
Screen output example:
A :
+2.00 -3.00 -8.00
+6.00 -1.00 -2.00
+3.00 -7.00 +5.00
+3.00 +2.00 +1.00
+6.00 -4.00 -1.00
Pinv = V * invS_T * U_T
-2.5492e-02 +8.6143e-02 -1.0818e-02 +7.7915e-02 +5.5473e-02
-5.7862e-02 +4.2756e-02 -9.3775e-02 +7.6606e-02 -1.4884e-02
-9.0331e-02 -5.1942e-03 +4.7848e-02 +2.6068e-02 -1.6535e-03
Press return to continue.
Pinv*A :
+1.00 +0.00 -0.00
-0.00 +1.00 +0.00
+0.00 -0.00 +1.00
Pinv*A*Pinv :
-0.0255 +0.0861 -0.0108 +0.0779 +0.0555
-0.0579 +0.0428 -0.0938 +0.0766 -0.0149
-0.0903 -0.0052 +0.0478 +0.0261 -0.0017
Pinv :
-0.0255 +0.0861 -0.0108 +0.0779 +0.0555
-0.0579 +0.0428 -0.0938 +0.0766 -0.0149
-0.0903 -0.0052 +0.0478 +0.0261 -0.0017
Press return to continue
Press X return to stop