@ptolomey wrote:

Hi cwillden,

Thank you for reply.

I bag your pardon for not emphasizing in previous post, that I am interested in finding **Negative Binomial** **Quantile **and **Hypergeometric Quantile **functions in JMP.

Please notify if you know how to calculate **Quantile **for these descrete distributions.

Thanks.

So, you want the inverse of the CDF then, correct? You want a function where you input a quantile and the distributional parameters and the function returns a value of the random variable that corresponds to the specified quantile? The functions I suggested are the CDF and take a value for the random variable and return the quantile. Just want to make sure we're on the same page.

If so, I don't believe there are built-in functions in JMP, and that may be because they would be a step function if the distribution is discrete. You could write your own quantile functions using loops to find the smallest value of your random variable that is greater than the desired quantile.

For example:

```
Hypergeometric Quantile = function({quantile, N_pop, K, n_samp},
x=0;
condition = 0;
while(!condition,
If(
Hypergeometric Distribution(N_pop, K, N_samp, x) >= quantile,
condition = 1,
x++
);
);
x
);
Hypergeometric Quantile(0.5, 100, 20, 10); //returns the value 2
```

-- Cameron Willden