Probability in Java (AnyLogic)

Question

I would like to simulate the probability of producing good products and also defects with let's say 80% probability.

I've seen that it's possible to generate numbers and see if they are equal to the probability I'm looking for. But I'm not that good at Java programming and AnyLogic is a bit different than Java in that I can't call libraries etc I think.

I have tried this but it doesn't work. Only parts_count keeps getting incremented but not parts_defect which stays at 0 during the whole simulation. What am I doing wrong? Thanks

double probability = normal();

if ( -2<probability || probability<2){
    parts_count += 1;
} else if ( -2>probability || probability>2){
    parts_defect +=1;
}

PS. normal() generates a normal distribution with sigma = 1 and mean = 0. I know 2*sigma is not equal to 80% I was just trying out for the sake of the example.

I just noticed that I made a mistake in the second <, you are totally correct! I also used abs() as Felipe pointed out which is cleaner! Thanks both! — Ismail, Sep 10 '20 at 08:40

score 1 · Accepted Answer · answered Sep 09 '20 at 16:06

1

That's because if ( -2<probability || probability<2){ is actually the same as saying that probability can take any value

you are saying probability bigger than -2 or probability smaller than 2... This is true for all the numbers of the world

Instead you should do

if( abs(probability)<2)
parts_count+=1;
else
parts_defects+=1;

answered Sep 09 '20 at 16:06

Felipe

8,311
2
15
31

Oh thanks for the answer, I'm new to Java so I didn't know abs() existed, that was my initial intention. It works now! Thanks again! – Ismail Sep 10 '20 at 08:38

Probability in Java (AnyLogic)

1 Answers1