Linear Algebra and the C Language/a0hw

Install and compile this file in your working directory.

/* ------------------------------------ */
/*  Save as :   c00d.c                  */
/* ------------------------------------ */
#include "v_a.h"
/* ------------------------------------ */
void fun(int rc)
{
double **A     = rupper_mR(i_mR(rc,rc),9);
double **invA  =           i_mR(rc,rc);
double **AinvA =           i_mR(rc,rc);

  clrscrn();

  printf(" A:");
  p_mR(A ,S4,P0,C6);

  printf(" invA:");
  pE_mR(invgj_mR(A,invA) ,S4,P5,C6);

  printf(" A invA:");
  p_mR(mul_mR(A,invA,AinvA) ,S4,P5,C6);
    
  f_mR(A);
  f_mR(invA);
  f_mR(AinvA);
}
/* ------------------------------------ */
int main(void)
{
time_t t;

  srand(time(&t));
  
   do 
         fun(rp_I(RC4)+RC1);
        
    while(stop_w());
        
  return 0;
}
/* ------------------------------------ */
/* ------------------------------------ */

The inverse of an upper triangular matrix

Screen output example:

                                                                                       
 A:
  -2   +3   +3   +5 
  +0   -3   -1   -5 
  +0   +0   +6   -4 
  +0   +0   +0   -4 

 invA:
-5.00000e-01 -5.00000e-01 +1.66667e-01 -1.66667e-01 
+0.00000e+00 -3.33333e-01 -5.55556e-02 +4.72222e-01 
-0.00000e+00 -0.00000e+00 +1.66667e-01 -1.66667e-01 
-0.00000e+00 -0.00000e+00 +0.00000e+00 -2.50000e-01 

 A invA:
+1.00000 +0.00000 +0.00000 +0.00000 
+0.00000 +1.00000 -0.00000 +0.00000 
+0.00000 +0.00000 +1.00000 +0.00000 
+0.00000 +0.00000 +0.00000 +1.00000 


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