Thread: More thoughts on random floats

I was reading this interesting thread about generating random ranges of floating point values.

What about closed ranges? I was wondering if a simple binary partitioning approach could be used.

Code:

#include "stdbool.h"

double random_within_range_with(bool (*extract_bit)(void*), void* data, double low, double high)
{
 if(low > high)
  return random_within_range_with(extract_bit, data, high, low);
 double range = (high - low) / 2;
 double sum = range;
 for(;;)
 {
  range /= 2;
  if(extract_bit(data))
   sum += range;
  else
   sum -= range;
  if(range == 0)
   break;
 }
 return low + sum;
}

#include "stdlib.h"
#include "time.h"

bool extract_srand_bit(void* unused)
{
 static bool init = true;
 if(init)
 {
  srand(time(NULL));
  init = false;
 }
 return rand() & 1;
}

double random_within_range(double low, double high)
{
 return random_within_range_with(extract_srand_bit, NULL, low, high);
}

#include "stdio.h"

int main(int argc, char** argv)
{
 puts("Random [LOW] [HIGH]");
 double low = -1;
 if(argc > 1)
  low = atof(argv[1]);
 double high = 1;
 if(argc > 2)
  high = atof(argv[2]);
 printf("Low: %g\n", low);
 printf("High: %g\n", high);
 for(;;)
 {
  printf(" %g\n", random_within_range(low, high));
  getchar();
 }
}

I'm trying to avoid platform-specific particularities. Does that look like an acceptable approach?