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@stdlib/stats

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Standard library statistical functions.

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{{alias}}( x, sigma ) Evaluates the cumulative distribution function (CDF) for a Rayleigh distribution with scale parameter `sigma` at a value `x`. If provided `NaN` as any argument, the function returns `NaN`. If provided a negative value for `sigma`, the function returns `NaN`. Parameters ---------- x: number Input value. sigma: number Scale parameter. Returns ------- out: number Evaluated CDF. Examples -------- > var y = {{alias}}( 2.0, 3.0 ) ~0.199 > y = {{alias}}( 1.0, 2.0 ) ~0.118 > y = {{alias}}( -1.0, 4.0 ) 0.0 > y = {{alias}}( NaN, 1.0 ) NaN > y = {{alias}}( 0.0, NaN ) NaN // Negative scale parameter: > y = {{alias}}( 2.0, -1.0 ) NaN // Degenerate distribution when `sigma = 0.0`: > y = {{alias}}( -2.0, 0.0 ) 0.0 > y = {{alias}}( 0.0, 0.0 ) 1.0 > y = {{alias}}( 2.0, 0.0 ) 1.0 {{alias}}.factory( sigma ) Returns a function for evaluating the cumulative distribution function (CDF) of a Rayleigh distribution with scale parameter `sigma`. Parameters ---------- sigma: number Scale parameter. Returns ------- cdf: Function Cumulative distribution function (CDF). Examples -------- > var myCDF = {{alias}}.factory( 0.5 ); > var y = myCDF( 1.0 ) ~0.865 > y = myCDF( 0.5 ) ~0.393 See Also --------