72 lines
1.3 KiB
Plaintext
72 lines
1.3 KiB
Plaintext
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{{alias}}( x, λ )
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Evaluates the probability mass function (PMF) for a Poisson
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distribution with mean parameter `λ` at a value `x`.
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If provided `NaN` as any argument, the function returns `NaN`.
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If provided a negative value for `λ`, the function returns `NaN`.
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Parameters
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----------
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x: number
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Input value.
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λ: number
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Mean parameter.
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Returns
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-------
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out: number
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Evaluated PMF.
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Examples
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--------
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> var y = {{alias}}( 4.0, 3.0 )
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~0.168
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> y = {{alias}}( 1.0, 3.0 )
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~0.149
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> y = {{alias}}( -1.0, 2.0 )
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0.0
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> y = {{alias}}( 0.0, NaN )
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NaN
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> y = {{alias}}( NaN, 0.5 )
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NaN
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// Negative mean parameter:
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> y = {{alias}}( 2.0, -0.5 )
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NaN
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// Degenerate distribution at `λ = 0`:
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> y = {{alias}}( 2.0, 0.0 )
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0.0
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> y = {{alias}}( 0.0, 0.0 )
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1.0
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{{alias}}.factory( λ )
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Returns a function for evaluating the probability mass function (PMF)
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of a Poisson distribution with mean parameter `λ`.
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Parameters
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----------
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λ: number
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Mean parameter.
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Returns
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-------
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pmf: Function
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Probability mass function (PMF).
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Examples
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--------
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> var mypmf = {{alias}}.factory( 1.0 );
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> var y = mypmf( 3.0 )
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~0.061
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> y = mypmf( 1.0 )
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~0.368
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See Also
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--------
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