411 REFERENCE · Wikibooks
Linear Algebra and the C Language/a0pb
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/* ------------------------------------ */
/* Save as : c00c.c */
/* ------------------------------------ */
#include "v_a.h"
/* ------------------------------------ */
#define RCA RC4
/* ------------------------------------ */
/* ------------------------------------ */
int main(void)
{
double a[RCA*RCA] ={
+0.812500000000, -0.656250000000, -1.406250000000, -0.656250000000,
-0.250000000000, +0.125000000000, -1.875000000000, -0.875000000000,
+0.125000000000, +0.437500000000, +1.937500000000, +0.437500000000,
-0.250000000000, -0.875000000000, -1.875000000000, +0.125000000000
};
double NVN[RCA*RCA] ={
+0.730296743340, -0.258198889747, -0.272165526976, -0.447213595500,
+0.547722557505, -0.258198889747, -0.680413817440, -0.596284794000,
-0.182574185835, +0.516397779494, +0.544331053952, +0.298142397000,
-0.365148371670, -0.774596669241, -0.408248290464, -0.596284794000
};
double **A = ca_A_mR(a, i_mR(RCA,RCA));
double **Nvn = ca_A_mR(NVN, i_mR(RCA,RCA));
double **invNvn = invgj_mR(Nvn, i_mR(RCA,RCA));
double **EValue = i_mR(RCA,RCA);
double **T = i_mR(RCA,RCA);
clrscrn();
printf(" A :");
p_mR(A, S9,P12, C4);
printf(" Nvn :");
p_mR(Nvn, S9,P12, C4);
printf(" Verify if:\n\n"
" EValue = invNvn * A * Nvn\n\n"
" EValue 1 EValue 2 EValue 3 EValue 4");
mul_mR(invNvn,A,T);
mul_mR(T,Nvn,EValue);
p_mR(EValue, S9,P12, C4);
stop();
clrscrn();
printf(" A :");
p_mR(A, S9,P12, C4);
printf(" Verify if:\n\n"
" A = Nvn EValue invNvn");
mul_mR(Nvn,EValue,T);
mul_mR(T,invNvn,A);
p_mR(A, S8,P12, C4);
stop();
clrscrn();
printf(" det(Nvn) = %.3e\n"
" det(Nvn) != 0 V1 and V2 and V3 and V4 are"
" linearly independent\n\n",
det_R(Nvn));
printf(" The matrix A projects the hyperspace in the direction\n"
" of the eigenvector V4 on a hyperplan determined by\n"
" the eigenvectors V1, V2 and V3 if :\n\n"
" The eigenvector V1 has its eigenvalue equal to one and \n"
" The eigenvector V2 has its eigenvalue equal to one and \n"
" The eigenvector V3 has its eigenvalue equal to one and \n"
" The eigenvector V4 has its eigenvalue equal to zero and \n\n"
" If The vectors V1, V2, V3, V4 are linearly independent\n\n");
stop();
f_mR(A);
f_mR(Nvn);
f_mR(invNvn);
f_mR(T);
f_mR(EValue);
return 0;
}
/* ------------------------------------ */
/* ------------------------------------ */
You verify the properties of the matrix A.
* The values of the eigenvalues: EValue = invNvn A Nvn
* The matrix: A = Nvn EValue invNvn
* If the column vectors of A are linearly independent
Screen output example:
A :
+0.812500000000 -0.656250000000 -1.406250000000 -0.656250000000
-0.250000000000 +0.125000000000 -1.875000000000 -0.875000000000
+0.125000000000 +0.437500000000 +1.937500000000 +0.437500000000
-0.250000000000 -0.875000000000 -1.875000000000 +0.125000000000
Nvn :
+0.730296743340 -0.258198889747 -0.272165526976 -0.447213595500
+0.547722557505 -0.258198889747 -0.680413817440 -0.596284794000
-0.182574185835 +0.516397779494 +0.544331053952 +0.298142397000
-0.365148371670 -0.774596669241 -0.408248290464 -0.596284794000
Verify if:
EValue = invNvn * A * Nvn
EValue 1 EValue 2 EValue 3 EValue 4
+1.000000000000 -0.000000000000 -0.000000000000 -0.000000000000
-0.000000000000 +1.000000000000 +0.000000000000 -0.000000000000
+0.000000000000 -0.000000000000 +1.000000000000 +0.000000000000
-0.000000000000 +0.000000000000 +0.000000000000 +0.000000000000
Press return to continue.
A :
+0.812500000000 -0.656250000000 -1.406250000000 -0.656250000000
-0.250000000000 +0.125000000000 -1.875000000000 -0.875000000000
+0.125000000000 +0.437500000000 +1.937500000000 +0.437500000000
-0.250000000000 -0.875000000000 -1.875000000000 +0.125000000000
Verify if:
A = Nvn EValue invNvn
+0.812500000000 -0.656250000000 -1.406250000000 -0.656250000000
-0.250000000000 +0.125000000000 -1.875000000000 -0.875000000000
+0.125000000000 +0.437500000000 +1.937500000000 +0.437500000000
-0.250000000000 -0.875000000000 -1.875000000000 +0.125000000000
Press return to continue.
det(Nvn) = -9.180e-02
det(Nvn) != 0 V1 and V2 and V3 and V4 are linearly independent
The matrix A projects the hyperspace in the direction
of the eigenvector V4 on a hyperplan determined by
the eigenvectors V1, V2 and V3 if :
The eigenvector V1 has its eigenvalue equal to one and
The eigenvector V2 has its eigenvalue equal to one and
The eigenvector V3 has its eigenvalue equal to one and
The eigenvector V4 has its eigenvalue equal to zero and
If The vectors V1, V2, V3, V4 are linearly independent
Press return to continue.