# Compute the Value of Poisson Quantile Function in R Programming – qpois() Function

• Last Updated : 25 Jun, 2020

`qpois()` function in R Language is used to compute the value of Poisson Quantile Function. It creates a quantile density plot for poisson distribution.

Syntax: qpois(vec, lambda)

Parameters:
vec: Sequence of integer values
lambda: Average number of events per interval

Example 1:

 `# R program to compute ``# Poisson Quantile Density`` ` `# Sequence of x-values``x <``-` `seq(``0``, ``1``, by ``=` `.``01``)`` ` `# Calling qpois() Function``y <``-` `qpois(x, ``lambda` `=` `5``)``y`

Output:

```  [1]   0   1   1   1   1   2   2   2   2   2   2   2   2   3   3   3   3   3
[19]   3   3   3   3   3   3   3   3   3   4   4   4   4   4   4   4   4   4
[37]   4   4   4   4   4   4   4   4   4   5   5   5   5   5   5   5   5   5
[55]   5   5   5   5   5   5   5   5   6   6   6   6   6   6   6   6   6   6
[73]   6   6   6   6   6   7   7   7   7   7   7   7   7   7   7   8   8   8
[91]   8   8   8   8   9   9   9  10  10  11 Inf
```

Example 2:

 `# R program to compute ``# Poisson Quantile Density`` ` `# Sequence of x-values``x <``-` `seq(``0``, ``1``, by ``=` `0.01``)`` ` `# Calling qpois() Function``y <``-` `qpois(x, ``lambda` `=` `15``)`` ` `# Plot a graph``plot(y)`

Output:

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