repl.txt (1595B)
1 2 {{alias}}( x, α, β ) 3 Evaluates the logarithm of the cumulative distribution function (CDF) for a 4 gamma distribution with shape parameter `α` and rate parameter `β` at a 5 value `x`. 6 7 If `α < 0` or `β <= 0`, the function returns `NaN`. 8 9 If provided `NaN` as any argument, the function returns `NaN`. 10 11 Parameters 12 ---------- 13 x: number 14 Input value. 15 16 α: number 17 Shape parameter. 18 19 β: number 20 Rate parameter. 21 22 Returns 23 ------- 24 out: number 25 Evaluated logCDF. 26 27 Examples 28 -------- 29 > var y = {{alias}}( 2.0, 0.5, 1.0 ) 30 ~-0.047 31 > y = {{alias}}( 0.1, 1.0, 1.0 ) 32 ~-2.352 33 > y = {{alias}}( -1.0, 4.0, 2.0 ) 34 -Infinity 35 36 > y = {{alias}}( NaN, 0.6, 1.0 ) 37 NaN 38 > y = {{alias}}( 0.0, NaN, 1.0 ) 39 NaN 40 > y = {{alias}}( 0.0, 1.0, NaN ) 41 NaN 42 43 // Negative shape parameter: 44 > y = {{alias}}( 2.0, -1.0, 1.0 ) 45 NaN 46 // Non-positive rate parameter: 47 > y = {{alias}}( 2.0, 1.0, -1.0 ) 48 NaN 49 50 51 {{alias}}.factory( α, β ) 52 Returns a function for evaluating the logarithm of the cumulative 53 distribution function (CDF) of a gamma distribution with shape parameter `α` 54 and rate parameter `β`. 55 56 Parameters 57 ---------- 58 α: number 59 Shape parameter. 60 61 β: number 62 Rate parameter. 63 64 Returns 65 ------- 66 logcdf: Function 67 Logarithm of cumulative distribution function (CDF). 68 69 Examples 70 -------- 71 > var mylogCDF = {{alias}}.factory( 6.0, 7.0 ); 72 > var y = mylogCDF( 2.0 ) 73 ~-0.006 74 75 See Also 76 -------- 77