@stdlib/stats
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Standard library statistical functions.
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{{alias}}( x, μ, σ )
Evaluates the probability density function (PDF) for a lognormal
distribution with location parameter `μ` and scale parameter `σ` at a value
`x`.
If provided `NaN` as any argument, the function returns `NaN`.
If provided `σ <= 0`, the function returns `NaN`.
Parameters
----------
x: number
Input value.
μ: number
Location parameter.
σ: number
Scale parameter.
Returns
-------
out: number
Evaluated PDF.
Examples
--------
> var y = {{alias}}( 2.0, 0.0, 1.0 )
~0.157
> y = {{alias}}( 1.0, 0.0, 1.0 )
~0.399
> y = {{alias}}( 1.0, 3.0, 1.0 )
~0.004
> y = {{alias}}( -1.0, 4.0, 2.0 )
0.0
> y = {{alias}}( NaN, 0.0, 1.0 )
NaN
> y = {{alias}}( 0.0, NaN, 1.0 )
NaN
> y = {{alias}}( 0.0, 0.0, NaN )
NaN
// Non-positive scale parameter `σ`:
> y = {{alias}}( 2.0, 0.0, -1.0 )
NaN
> y = {{alias}}( 2.0, 0.0, 0.0 )
NaN
{{alias}}.factory( μ, σ )
Returns a function for evaluating the probability density function (PDF) of
a lognormal distribution with location parameter `μ` and scale parameter
`σ`.
Parameters
----------
μ: number
Location parameter.
σ: number
Scale parameter.
Returns
-------
pdf: Function
Probability density function (PDF).
Examples
--------
> var myPDF = {{alias}}.factory( 4.0, 2.0 );
> var y = myPDF( 10.0 )
~0.014
> y = myPDF( 2.0 )
~0.025
See Also
--------