@stdlib/stats
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Standard library statistical functions.
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{{alias}}( p, λ )
Evaluates the quantile function for a Poisson distribution with mean
parameter `λ` at a probability `p`.
If `p < 0` or `p > 1`, the function returns `NaN`.
If provided `NaN` as any argument, the function returns `NaN`.
If provided a negative value for `λ`, the function returns `NaN`.
Parameters
----------
p: number
Input probability.
λ: number
Mean parameter.
Returns
-------
out: number
Evaluated quantile function.
Examples
--------
> var y = {{alias}}( 0.5, 2.0 )
2
> y = {{alias}}( 0.9, 4.0 )
7
> y = {{alias}}( 0.1, 200.0 )
182
> y = {{alias}}( 1.1, 0.0 )
NaN
> y = {{alias}}( -0.2, 0.0 )
NaN
> y = {{alias}}( NaN, 0.5 )
NaN
> y = {{alias}}( 0.0, NaN )
NaN
// Negative mean parameter:
> y = {{alias}}( 2.0, -1.0 )
NaN
// Degenerate distribution at `λ = 0`:
> y = {{alias}}( 0.1, 0.0 )
0.0
> y = {{alias}}( 0.9, 0.0 )
0.0
{{alias}}.factory( λ )
Returns a function for evaluating the quantile function of a Poisson
distribution with mean parameter `λ`.
Parameters
----------
λ: number
Mean parameter.
Returns
-------
quantile: Function
Quantile function.
Examples
--------
> var myQuantile = {{alias}}.factory( 0.4 );
> var y = myQuantile( 0.4 )
0.0
> y = myQuantile( 1.0 )
Infinity
See Also
--------