@stdlib/stats
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Standard library statistical functions.
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{{alias}}( x, r, p )
Evaluates the natural logarithm of the probability mass function (PMF) for a
negative binomial distribution with number of successes until experiment is
stopped `r` and success probability `p` at a value `x`.
If provided `NaN` as any argument, the function returns `NaN`.
If provided a `r` which is not a positive number, the function returns
`NaN`.
If provided a success probability `p` outside of `[0,1]`, the function
returns `NaN`.
Parameters
----------
x: number
Input value.
r: number
Number of successes until experiment is stopped.
p: number
Success probability.
Returns
-------
out: number
Evaluated logPMF.
Examples
--------
> var y = {{alias}}( 5.0, 20.0, 0.8 )
~-1.853
> y = {{alias}}( 21.0, 20.0, 0.5 )
~-2.818
> y = {{alias}}( 5.0, 10.0, 0.4 )
~-4.115
> y = {{alias}}( 0.0, 10.0, 0.9 )
~-1.054
> y = {{alias}}( 21.0, 15.5, 0.5 )
~-3.292
> y = {{alias}}( 5.0, 7.4, 0.4 )
~-2.976
> y = {{alias}}( 2.0, 0.0, 0.5 )
NaN
> y = {{alias}}( 2.0, -2.0, 0.5 )
NaN
> y = {{alias}}( 2.0, 20, -1.0 )
NaN
> y = {{alias}}( 2.0, 20, 1.5 )
NaN
> y = {{alias}}( NaN, 20.0, 0.5 )
NaN
> y = {{alias}}( 0.0, NaN, 0.5 )
NaN
> y = {{alias}}( 0.0, 20.0, NaN )
NaN
{{alias}}.factory( r, p )
Returns a function for evaluating the natural logarithm of the probability
mass function (PMF) of a negative binomial distribution with number of
successes until experiment is stopped `r` and success probability `p`.
Parameters
----------
r: number
Number of successes until experiment is stopped.
p: number
Success probability.
Returns
-------
logpmf: Function
Logarithm of probability mass function (PMF).
Examples
--------
> var mylogPMF = {{alias}}.factory( 10, 0.5 );
> var y = mylogPMF( 3.0 )
~-3.617
> y = mylogPMF( 5.0 )
~-2.795
See Also
--------