Linear Algebra and the C Language/a03l
Install and compile this file in your working directory.
/* ------------------------------------ */
/* Save as: c01a.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 = Pinv_Rn_mR(A, i_mR(CA,RA),FACTOR_E);;
double **Ide = mul_mR(Pinv,A, i_mR(CA,CA)); ;
clrscrn();
printf(" A:");
p_mR(A, S7,P2,C7);
printf(" Pinv = V invS_T U_T ");
pE_mR(Pinv, S12,P4,C10);
printf(" Ide = Pinv A (The left inverse of A)");
p_mR(Ide, S7,P2,C10);
f_mR(A);
f_mR(Pinv);
f_mR(Ide);
}
/* ------------------------------------ */
int main(void)
{
time_t t;
srand(time(&t));
do
{
fun();
} while(stop_w());
return 0;
}
/* ------------------------------------ */
/* ------------------------------------ */
Screen output example:
A :
-9.00 -9.00 -9.00
-1.00 -3.00 +4.00
-8.00 -4.00 +1.00
-2.00 +2.00 +5.00
-1.00 +6.00 +4.00
Pinv = V * invS_T * U_T
-4.4894e-02 +3.7031e-02 -6.0278e-02 -3.7050e-02 -7.6661e-02
+5.4343e-03 -1.1026e-01 -9.0613e-03 +1.2118e-02 +1.0961e-01
-5.0855e-02 +9.2656e-02 +3.7499e-02 +4.2000e-02 -1.8955e-02
Ide = Pinv * A (The left inverse of A)
+1.00 +0.00 +0.00
+0.00 +1.00 +0.00
-0.00 -0.00 +1.00
Press return to continue
Press X return to stop