Linear Algebra and the C Language/a0cm

/* ------------------------------------ */
/*  Save as :  c00a.c                   */
/* ------------------------------------ */
#include "v_a.h"
/* ------------------------------------ */
#define   RCA C3
/* ------------------------------------ */
int main(void)
{
double a[RCA*RCA]={
+3,-1,+2,
-1,+4,+3,
+2,+3,+7
};

double R = 6;

double **A        =      ca_A_mR(a,       i_mR(RCA,RCA));
double **EVector  =    eigs_V_mR(A,       i_mR(RCA,RCA));  
double **EVectorT = transpose_mR(EVector, i_mR(RCA,RCA));

double **T1       =                       i_mR(RCA,RCA);
double **T2       =                       i_mR(RCA,RCA);

  clrscrn();
  printf(" If %+.0fx^2 %+.0fy^2 %+.0fz^2 "
         " %+.0fxy %+.0fxz %+.0fyz= %+.0f \n\n"
         " Can you give a description of the curve "
         " in the standar basis?\n\n",
                A[R1][C1],     A[R2][C2],     A[R3][C3], 
             2*(A[R2][C1]), 2*(A[R3][C1]), 2*(A[R3][C2]), R);  

  printf(" A:");
  p_mR(A,S10,P4,C6);
  
  printf(" EVector:");
  p_mR(EVector,S10,P4,C6);

  printf(" EValue : EVectorT A EVector");     
  mul_mR(EVectorT,A,T1);
  mul_mR(T1,EVector,T2);
  p_mR(T2,S10,P4,C6);  

  printf(" Then : %+.3f x^2 %+.3f y^2 %+.3f z^2 = %+.3f \n\n"
         " It is an ellipsoid\n\n",
           T2[R1][C1], T2[R2][C2], T2[R3][C3], R); 
  stop();
   
  f_mR(A);
  
  f_mR(EVector);
  f_mR(EVectorT);
   
  f_mR(T1);
  f_mR(T2);
  
  return 0;
}
/* ------------------------------------ */
/* ------------------------------------ */

                                                                                       
 If +3x^2 +4y^2 +7z^2  -2xy +4xz +6yz= +6 

 Can you give a description of the curve  in the standar basis?

 A:
   +3.0000    -1.0000    +2.0000 
   -1.0000    +4.0000    +3.0000 
   +2.0000    +3.0000    +7.0000 

 EVector:
   +0.2058    +0.7416    +0.6385 
   +0.4658    -0.6481    +0.6026 
   +0.8607    +0.1734    -0.4788 

 EValue : EVectorT A EVector
   +9.1017    -0.0000    +0.0000 
   -0.0000    +4.3416    +0.0000 
   -0.0000    +0.0000    +0.5567 

 Then : +9.102 x^2 +4.342 y^2 +0.557 z^2 = +6.000 

 It is an ellipsoid

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