Linear Algebra and the C Language/a0m1
Install and compile this file in your working directory.
/* ------------------------------------ */
/* Save as : c02b.c */
/* ------------------------------------ */
#include "v_a.h"
/* ------------------------------------ */
#define RCA RC4
/* ------------------------------------ */
#define EV R2
/* ------------------------------------ */
int main(void)
{
double a[RCA*RCA]={
+5.701637292731, +0.991969965586, +0.254041088748, +1.125039107310,
+0.991969965586, +6.402440296173, +0.359161539264, +1.590572531025,
+0.254041088748, +0.359161539264, +5.091980394202, +0.407341745750,
+1.125039107310, +1.590572531025, +0.407341745750, +6.803942016894
};
double **A = ca_A_mR(a, i_mR(RCA,RCA));
double **EValue = eigs_mR(A, i_mR(RCA,RCA));
double **Ide = eye_mR( i_mR(RCA,RCA));
double **sIde = smul_mR(EValue[EV][C1],Ide, i_mR(RCA,RCA));
double **AmnssIde = sub_mR(A,sIde, i_mR(RCA,RCA));
double **b = m0_mR(i_mR(RCA,C1));
double **Ab = c_A_b_Ab_mR(AmnssIde,b, i_Abr_Ac_bc_mR(RCA,RCA,C1));
double **Ab_free = i_Abr_Ac_bc_mR(RCA,RCA,RCA);
double **b_free = i_mR(RCA,RCA);
double **V = i_mR(RCA,RCA);
clrscrn();
printf(" The eigenvectors associated with eigenvalues\n"
" with multiple multiplicity are not unique. \n"
" There exist several set of unit vectors that\n"
" correspond to the same eigenspace. \n\n\n"
" A:");
p_mR(A,S10,P5,C10);
gj_PP_mR(Ab,YES);
put_zeroR_mR(Ab,Ab_free);
put_freeV_mR(Ab_free);
gj_PP_mR(Ab_free,YES);
c_Ab_b_mR(Ab_free,b_free);
c_c_mR(b_free,C2,V,EV);
c_c_mR(b_free,C3,V,EV+C1);
c_c_mR(b_free,C4,V,EV+C2);
Normalize_mR(V);
printf("\n\n\n"
" Copy V%d into the last file\n\n"
" V%d:",EV,EV);
P_mR(V,S10,P12,C10);
stop();
f_mR(A);
f_mR(EValue);
f_mR(Ide);
f_mR(sIde);
f_mR(AmnssIde);
f_mR(Ab);
f_mR(b);
f_mR(Ab_free);
f_mR(b_free);
f_mR(V);
return 0;
}
/* ------------------------------------ */
/* ------------------------------------ */
Screen output example:
The eigenvectors associated with eigenvalues
with multiple multiplicity are not unique.
There exist several set of unit vectors that
correspond to the same eigenspace.
A:
+5.70164 +0.99197 +0.25404 +1.12504
+0.99197 +6.40244 +0.35916 +1.59057
+0.25404 +0.35916 +5.09198 +0.40734
+1.12504 +1.59057 +0.40734 +6.80394
Copy V2 into the last file
V2:
-nan, -0.816415639507, -0.340441083605, -0.848510478701,
-nan, +0.577464720627, +0.000000000000, +0.000000000000,
-nan, +0.000000000000, +0.940265849956, +0.000000000000,
-nan, +0.000000000000, +0.000000000000, +0.529178578114
Press return to continue.