• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 371
  • Last Modified:

C Random Numbers 0.0 to 1.0

Hi,
I need to generate random numbers using C in the following range:
0.0 <= X <= 1.0

That will give us the following possible values
0.0
0.1
0.2
...
0.9
1.0

So far, I have been able to generate random numbers, but not to the tenth place.  If anyone knows how to modify my code, or write better code, that is what I need.  Here is my code:

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>
int main() {
srand(time(NULL));

double rnum;
int i;

for(i=0; i<=20; i++) {
    rnum = 1.1 * (float) rand() / (float) RAND_MAX;
    printf("Number: %lf\n", rnum);
}

return 0;
}

0
deadite
Asked:
deadite
  • 2
  • 2
2 Solutions
 
marchentCommented:
>>rnum = 1.1 * (float) rand() / (float) RAND_MAX;
rnum = (float)(rand() % 11) /10;

~marchent~
0
 
deaditeAuthor Commented:
marchent,

That worked perfect, except my printf line still outputs the extra 0's.  Is there a way to get rid of them?  For example:

0.600000
1.000000
0.200000

Thanks
0
 
ozoCommented:
printf("Number: %.1f\n", rnum);
0
 
deaditeAuthor Commented:
Ozo,
Sorry for the confusion.  I meant get rid of the extra 0's so the number stored is X.X  not X.XXXXXX.  However, your printline shows the results I need, but doesn't store the ones I need.

Thanks
0
 
ozoCommented:
I'm sorry, I don't understand what you mean when you say the number stored is X.X  not X.XXXXXX
the number is not stored as a string of ASCII digits, the number is stored as a float,
which probably does not even have an exact representation for 0.1
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Featured Post

What Kind of Coding Program is Right for You?

There are many ways to learn to code these days. From coding bootcamps like Flatiron School to online courses to totally free beginner resources. The best way to learn to code depends on many factors, but the most important one is you. See what course is best for you.

  • 2
  • 2
Tackle projects and never again get stuck behind a technical roadblock.
Join Now