repl.txt (2289B)
1 2 {{alias}}( [α, β] ) 3 Returns a gamma distribution object. 4 5 Parameters 6 ---------- 7 α: number (optional) 8 Shape parameter. Must be greater than `0`. Default: `1.0`. 9 10 β: number (optional) 11 Rate parameter. Must be greater than `0`. Default: `1.0`. 12 13 Returns 14 ------- 15 gamma: Object 16 Distribution instance. 17 18 gamma.alpha: number 19 Shape parameter. If set, the value must be greater than `0`. 20 21 gamma.beta: number 22 Rate parameter. If set, the value must be greater than `0`. 23 24 gamma.entropy: number 25 Read-only property which returns the differential entropy. 26 27 gamma.kurtosis: number 28 Read-only property which returns the excess kurtosis. 29 30 gamma.mean: number 31 Read-only property which returns the expected value. 32 33 gamma.mode: number 34 Read-only property which returns the mode. 35 36 gamma.skewness: number 37 Read-only property which returns the skewness. 38 39 gamma.stdev: number 40 Read-only property which returns the standard deviation. 41 42 gamma.variance: number 43 Read-only property which returns the variance. 44 45 gamma.cdf: Function 46 Evaluates the cumulative distribution function (CDF). 47 48 gamma.logcdf: Function 49 Evaluates the natural logarithm of the cumulative distribution function 50 (CDF). 51 52 gamma.logpdf: Function 53 Evaluates the natural logarithm of the probability density function 54 (PDF). 55 56 gamma.mgf: Function 57 Evaluates the moment-generating function (MGF). 58 59 gamma.pdf: Function 60 Evaluates the probability density function (PDF). 61 62 gamma.quantile: Function 63 Evaluates the quantile function at probability `p`. 64 65 Examples 66 -------- 67 > var gamma = {{alias}}( 6.0, 5.0 ); 68 > gamma.alpha 69 6.0 70 > gamma.beta 71 5.0 72 > gamma.entropy 73 ~0.647 74 > gamma.kurtosis 75 1.0 76 > gamma.mean 77 1.2 78 > gamma.mode 79 1.0 80 > gamma.skewness 81 ~0.816 82 > gamma.stdev 83 ~0.49 84 > gamma.variance 85 0.24 86 > gamma.cdf( 0.8 ) 87 ~0.215 88 > gamma.logcdf( 0.8 ) 89 ~-1.538 90 > gamma.logpdf( 1.0 ) 91 ~-0.131 92 > gamma.mgf( -0.5 ) 93 ~0.564 94 > gamma.pdf( 1.0 ) 95 ~0.877 96 > gamma.quantile( 0.8 ) 97 ~1.581 98 99 See Also 100 -------- 101