Linear Algebra and the C Language/a0e8

Install and compile this file in your working directory.

/* ------------------------------------ */
/*  Save as :   c00d.c                  */
/* ------------------------------------ */
#include "v_a.h"
/* ------------------------------------	*/
/* ------------------------------------ 
 Positive and negative floating point number 
 
    e=  1E-0  -> 1234
    e = 1E-1  ->  123.4
    e = 1E-2  ->   12.34
    e = 1E-3  ->    1.234
   ------------------------------------ */
double X_r_E(
int maxI,
double e)
{
double x;

    x  = (rand() % maxI) + 1 ; /* + 1 : not zero */
    x *=  pow(-1,rand()) * e;  /*  sign + or -   */

 return(x);
}
/* ------------------------------------ */
/* ------------------------------------ */  
int main(void)
{
time_t t;

  srand(time(&t));
  
	do{
		
 clrscrn();       
 printf(" Decimal numbers:           \n");    			
 printf(" r_E(999, 1e-3):  %+0.3f\n\n\n", r_E(999, 1e-3));
 
 printf(" Scientific Notation :     %%+0.3E ... \%%+0.3e \n\n");
 
 printf(" Positive and negative numbers: \n");  		
 printf(" r_E(999, 1e-3):  %+0.3e    \n", r_E(999, 1e-3));
 printf(" r_E(999, 1E+3):  %+0.3E\n\n\n", r_E(999, 1E+3));

 printf(" Positive numbers: \n"); 
 printf(" rp_E(999, 1e-3): %+0.3e    \n", rp_E(999, 1e-3));
 printf(" rp_E(999, 1E+3): %+0.3E\n\n\n", rp_E(999, 1E+3));
 
    }while(stop_w());
		
  return 0;
}
/* ------------------------------------ */
/* ------------------------------------ */

I rename the function studied with the prefix X_ to differentiate it from the one with the same name in the library.

Screen output example:

                                                                                       
 Decimal numbers:           
 r_E(999, 1e-3):  +0.183


 Scientific Notation :     %+0.3E ... %+0.3e 

 Positive and negative numbers: 
 r_E(999, 1e-3):  -4.940e-01    
 r_E(999, 1E+3):  +8.880E+05


 Positive numbers: 
 rp_E(999, 1e-3): +8.070e-01    
 rp_E(999, 1E+3): +8.360E+05



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