Linear Algebra and the C Language/a0l1


Install and compile this file in your working directory.

/* ------------------------------------ */
/*  Save as:   c00d.c                   */
/* ------------------------------------ */
#include "v_a.h"
/* ------------------------------------ */
/* ------------------------------------ */
void X_gj3_T_mR(
double **Ab,
int above
)
{
int r= R1;
int c= C1;

   while( (r<Ab[R_SIZE][C0]) &&
           (c<Ab[C_SIZE_A][C0]) )
       {
        if(pivotbest_gj3Ab_mR(Ab,r,c)>ERROR_E) 

           zero_under_pivot_gj3Ab_mR(Ab,r,c);
 
        else r--;
        
        r++;
        c++;
       }

 r = Ab[R_SIZE][C0];
 
 if(above)
 
 while(r>R2)
  {
   r--;
   c=C1;
   
   while(fabs(Ab[r][c])<ERROR_E  &&  c<(Ab[C_SIZE_A][C0]-C1) ) c++;
         
         
   if(fabs(Ab[r][c])>ERROR_E)
   {
	  printf(" Ab: pivot[%d][[%d] ",r,c); 
      p_mR(Ab,S8,P4,C8);	 
       	   
      zero_above_pivot_gj3Ab_mR(Ab,r,c);
      
      printf(" Ab: pivot[%d][[%d]"
             "      zero_above_pivot_gj1Ab_mR();",r,c); 
      p_mR(Ab,S8,P4,C8);	
      stop();
      clrscrn();          
    }
  }
}
/* ------------------------------------ */
double **X_gj_PP_mR(
double **Ab,
int above
)
{
   X_gj3_T_mR(Ab,above);
  
return(Ab);
}
/* ------------------------------------ */
/* ------------------------------------ */
void fun(int r)
{
double **A  =        r_mR(     i_mR(r,r),999.);
double **b  =        r_mR(     i_mR(r,C1),999.);
double **Ab = c_A_b_Ab_mR(A,b, i_Abr_Ac_bc_mR(  r,  r, C1));;
/*                             i_Abr_Ac_bc_mR(RAb, CA, Cb)); */
  
  clrscrn();
  printf(" Copy/Paste into the octave window.\n\n");
  p_Octave_mR(Ab,"Ab",P0);
  printf("\n rref(Ab,.00000000001)\n\n");
  stop();

  clrscrn();
  X_gj_PP_mR(Ab,YES);
  printf("  gj_PP_mR(Ab,YES);");
  p_mR(Ab,S10,P4,C7);
  
  
  f_mR(Ab);
  f_mR(b);
  f_mR(A);
}
/* ------------------------------------ */
int main(void)
{
time_t t;

  srand(time(&t));
do
{
  fun(R6);


} while(stop_w());

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

Screen output example:

                                                                                       
 Copy/Paste into the octave window.

 Ab=[
-334,+54,+409,+688,+310;
-313,+959,+202,-367,+710;
+335,+854,+794,-971,+114;
-73,+946,-507,-468,-818]


 rref(Ab,.00000000001)

 Press return to continue. 


 Ab: pivot[4][[4] 
 +1.0000  +2.5493  +2.3701  -2.8985  +0.3403 
 +0.0000  +1.0000  +0.5372  -0.7253  +0.4647 
 -0.0000  -0.0000  +1.0000  -0.1502  +1.4003 
 +0.0000  +0.0000  +0.0000  +1.0000  -2.0610 

 Ab: pivot[4][[4]      zero_above_pivot_gj1Ab_mR();
 +1.0000  +2.5493  +2.3701  +0.0000  -5.6337 
 +0.0000  +1.0000  +0.5372  +0.0000  -1.0301 
 +0.0000  -0.0000  +1.0000  +0.0000  +1.0908 
 +0.0000  +0.0000  +0.0000  +1.0000  -2.0610 

 Press return to continue. 


 Ab: pivot[3][[3] 
 +1.0000  +2.5493  +2.3701  +0.0000  -5.6337 
 +0.0000  +1.0000  +0.5372  +0.0000  -1.0301 
 +0.0000  -0.0000  +1.0000  +0.0000  +1.0908 
 +0.0000  +0.0000  +0.0000  +1.0000  -2.0610 

 Ab: pivot[3][[3]      zero_above_pivot_gj1Ab_mR();
 +1.0000  +2.5493  +0.0000  +0.0000  -8.2190 
 +0.0000  +1.0000  +0.0000  +0.0000  -1.6161 
 +0.0000  -0.0000  +1.0000  +0.0000  +1.0908 
 +0.0000  +0.0000  +0.0000  +1.0000  -2.0610 

 Press return to continue. 


 Ab: pivot[2][[2] 
 +1.0000  +2.5493  +0.0000  +0.0000  -8.2190 
 +0.0000  +1.0000  +0.0000  +0.0000  -1.6161 
 +0.0000  -0.0000  +1.0000  +0.0000  +1.0908 
 +0.0000  +0.0000  +0.0000  +1.0000  -2.0610 

 Ab: pivot[2][[2]      zero_above_pivot_gj1Ab_mR();
 +1.0000  -0.0000  +0.0000  +0.0000  -4.0992 
 +0.0000  +1.0000  +0.0000  +0.0000  -1.6161 
 +0.0000  -0.0000  +1.0000  +0.0000  +1.0908 
 +0.0000  +0.0000  +0.0000  +1.0000  -2.0610 

 Press return to continue. 


  gj_PP_mR(Ab,YES);
   +1.0000    -0.0000    +0.0000    +0.0000    -4.0992 
   +0.0000    +1.0000    +0.0000    +0.0000    -1.6161 
   +0.0000    -0.0000    +1.0000    +0.0000    +1.0908 
   +0.0000    +0.0000    +0.0000    +1.0000    -2.0610 


 Press   return to continue
 Press X return to stop