Linear Algebra and the C Language/a0im

Install and compile this file in your working directory.

/* ------------------------------------ */
/*  Save as :   c00a.c                  */
/* ------------------------------------ */
#include "v_a.h"
/* ------------------------------------ */
#define  RC RC3
/* ------------------------------------ */
int main(void)
{
double a[RC*RC] ={ 1,2,3,
                   5,4,1,
                   7,2,5};
                     
/* ---------- Copy "a" into A --------- */                        
double **A   = ca_A_mR(a,i_mR(RC,RC));
/* ------------------------------------ */

double **Inv =           i_mR(RC,RC);
double **ID  =           i_mR(RC,RC);

  clrscrn();
  printf(" Copy/Paste into the octave window.\n\n");
  p_Octave_mR(A,"A",P0);
  printf(" inv(A)\n\n\n\n");
  
  printf(" inv(A):");    
  pE_mR(inv_mR(A,Inv), S12,P4,C3);

  printf(" A inv(A):");  
  p_mR(mul_mR(A,Inv,ID), S8,P4,C3);
  
  stop();

  f_mR(ID);
  f_mR(Inv);
  f_mR(A);

  return 0;
}
/* ------------------------------------ */
/* ------------------------------------ */

Screen output example:

                                                                                       
 Copy/Paste into the octave window.

 A=[
+1,+2,+3;
+5,+4,+1;
+7,+2,+5]

 inv(A)



 inv(A):
 -2.5000e-01  +5.5556e-02  +1.3889e-01 
 +2.5000e-01  +2.2222e-01  -1.9444e-01 
 +2.5000e-01  -1.6667e-01  +8.3333e-02 

 A inv(A):
 +1.0000  +0.0000  +0.0000 
 +0.0000  +1.0000  +0.0000 
 -0.0000  -0.0000  +1.0000 

 Press return to continue.