# How do I evaluate a probability mass function from Distributions?

**URL:** <https://discourse.julialang.org/t/how-do-i-evaluate-a-probability-mass-function-from-distributions/89673>\
**Category:** General Usage\
**Tags:** question\
**Created:** [November 2, 2022, 8:19pm UTC](https://discourse.julialang.org/t/how-do-i-evaluate-a-probability-mass-function-from-distributions/89673 "2022-11-02T20:19:57Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![prittjam](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/prittjam/32/21267_2.png) [@prittjam](https://discourse.julialang.org/u/prittjam)\
**Post date:** [November 2, 2022, 8:19pm UTC](https://discourse.julialang.org/t/how-do-i-evaluate-a-probability-mass-function-from-distributions/89673/1 "2022-11-02T20:19:57Z")

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I get 0

```julia
p=Distributions.Hypergeometric(100, 100, 200)
 Hypergeometric(ns=100, nf=100, n=200)

pdf(p,4)
 0.0

```

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**Author:** ![Dan](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/dan/32/42581_2.png) [@Dan](https://discourse.julialang.org/u/Dan)\
**Post date:** [November 2, 2022, 8:24pm UTC](https://discourse.julialang.org/t/how-do-i-evaluate-a-probability-mass-function-from-distributions/89673/2 "2022-11-02T20:24:12Z")

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Well, `0.0` is the correct answer. As you have:

```julia
julia> pdf(p,100)
1.0

```

For details on this distribution, press `?` in REPL and then `Distributions.Hypergeometric(100, 100, 200)`. The description will make it clear.

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<div class="post-metadata">

**Author:** ![prittjam](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/prittjam/32/21267_2.png) [@prittjam](https://discourse.julialang.org/u/prittjam)\
**Post date:** [November 2, 2022, 8:26pm UTC](https://discourse.julialang.org/t/how-do-i-evaluate-a-probability-mass-function-from-distributions/89673/3 "2022-11-02T20:26:17Z")

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of course, ok silly mistake. thanks.