set the double value using Random class

[blazzer]

Hi,

I need help. I just wondering whether i can set the double value using random class..i even use if statement to set it..but nothing..i wanna set between 0.5 n 0.7 value..

double planetMass = 0.0;
double sunMass = 0.0;
Random rdm = new Random();
double rand = rdm.nextDouble();

if (rand >= 0.5 && rand <= 0.7){
likeliHood = (rand * planetMass) / sunMass;
}else{
rand = rdm.nextDouble();
}

please helpp...

Thanks

[JosAH]

Hi,

I need help. I just wondering whether i can set the double value using random class..i even use if statement to set it..but nothing..i wanna set between 0.5 n 0.7 value..

double planetMass = 0.0;
double sunMass = 0.0;
Random rdm = new Random();
double rand = rdm.nextDouble();

if (rand >= 0.5 && rand <= 0.7){
likeliHood = (rand * planetMass) / sunMass;
}else{
rand = rdm.nextDouble();
}

please helpp...

Thanks

This is the canonical trick: the nextDouble() method returns a number in the
interval R= [0,1). You can compute a number in the range [L,H) as follows:

r in R so (H-L)*r+L in [L,H)

So you have to do this 0.2*r+0.5 to get a uniformly distributed number in the
range [0.5,0.7)

kind regards,

Jos

[blazzer]

Thx A LOT!! It workss!!