How to subtract 0.5 from this random

[skittlesaddictx50v]

How do I make it randomize a -0.5 in addition to the 0.5? In other words how do I make it randomize so the output is sometimes 1.5, 2.0, 2.5, 1.5, 2.0 when I enter 2 into the program? I can only get it to add 0.5. Hope that makes sense

#include <iostream>
#include <cstdlib>
#include <ctime>
using namespace std; 

int main()
{
    double r;
	int user_in;

	cout <<"enter number" << endl;
	cin >> user_in;
    
    
    srand(time(0));
    for (int i=0; i<=11; i++)
    {
        r=rand() %2 * 0.5 + user_in;
        cout << r << endl;
    }
	

system("pause");
return 0;
}

[Texan40]

#include <iostream>
#include <cstdlib>
#include <ctime>
using namespace std;

int main()
{
    double r;
	int user_in;

	cout <<"enter number" << endl;
	cin >> user_in;


    srand(time(0));
    for (int i=0; i<=11; i++)
    {
        r= (rand() % 2 ? 0.5 : 0.0) + rand() % user_in;
        cout << r << endl;
    }
return 0;
}

[skittlesaddictx50v]

you're the man