@stdlib/stats
Version:
Standard library statistical functions.
84 lines (65 loc) • 1.8 kB
Plain Text
{{alias}}( x, a, b )
Evaluates the natural logarithm of the probability density function (PDF)
for Kumaraswamy's double bounded distribution with first shape parameter `a`
and second shape parameter `b` at a value `x`.
If provided `NaN` as any argument, the function returns `NaN`.
If `a <= 0` or `b <= 0`, the function returns `NaN`.
Parameters
----------
x: number
Input value.
a: number
First shape parameter.
b: number
Second shape parameter.
Returns
-------
out: number
Evaluated logPDF.
Examples
--------
> var y = {{alias}}( 0.5, 1.0, 1.0 )
0.0
> y = {{alias}}( 0.5, 2.0, 4.0 )
~0.523
> y = {{alias}}( 0.2, 2.0, 2.0 )
~-0.264
> y = {{alias}}( 0.8, 4.0, 4.0 )
~0.522
> y = {{alias}}( -0.5, 4.0, 2.0 )
-Infinity
> y = {{alias}}( 1.5, 4.0, 2.0 )
-Infinity
> y = {{alias}}( 2.0, -1.0, 0.5 )
NaN
> y = {{alias}}( 2.0, 0.5, -1.0 )
NaN
> y = {{alias}}( NaN, 1.0, 1.0 )
NaN
> y = {{alias}}( 0.0, NaN, 1.0 )
NaN
> y = {{alias}}( 0.0, 1.0, NaN )
NaN
{{alias}}.factory( a, b )
Returns a function for evaluating the natural logarithm of the probability
density function (PDF) of a Kumaraswamy's double bounded distribution with
first shape parameter `a` and second shape parameter `b`.
Parameters
----------
a: number
First shape parameter.
b: number
Second shape parameter.
Returns
-------
logpdf: Function
Logarithm of probability density function (PDF).
Examples
--------
> var mylogpdf = {{alias}}.factory( 0.5, 1.0 );
> var y = mylogpdf( 0.8 )
~-0.582
> y = mylogpdf( 0.3 )
~-0.091
See Also
--------