@stdlib/stats
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Standard library statistical functions.
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{{alias}}( x, μ, σ )
Evaluates the natural logarithm of 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 logPDF.
Examples
--------
> var y = {{alias}}( 2.0, 0.0, 1.0 )
~-1.852
> y = {{alias}}( 1.0, 0.0, 1.0 )
~-0.919
> y = {{alias}}( 1.0, 3.0, 1.0 )
~-5.419
> y = {{alias}}( -1.0, 4.0, 2.0 )
-Infinity
> 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 natural logarithm of 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
-------
logpdf: Function
Logarithm of probability density function (PDF).
Examples
--------
> var mylogPDF = {{alias}}.factory( 4.0, 2.0 );
> var y = mylogPDF( 10.0 )
~-4.275
> y = mylogPDF( 2.0 )
~-3.672
See Also
--------