repl.txt (1782B)
1 2 {{alias}}( x, α, β ) 3 Evaluates the natural logarithm of the probability density function (PDF) 4 for a beta distribution with first shape parameter `α` and second shape 5 parameter `β` at a value `x`. 6 7 If provided `NaN` as any argument, the function returns `NaN`. 8 9 If `α <= 0` or `β <= 0`, the function returns `NaN`. 10 11 Parameters 12 ---------- 13 x: number 14 Input value. 15 16 α: number 17 First shape parameter. 18 19 β: number 20 Second shape parameter. 21 22 Returns 23 ------- 24 out: number 25 Natural logarithm of the PDF. 26 27 Examples 28 -------- 29 > var y = {{alias}}( 0.5, 1.0, 1.0 ) 30 0.0 31 > y = {{alias}}( 0.5, 2.0, 4.0 ) 32 ~0.223 33 > y = {{alias}}( 0.2, 2.0, 2.0 ) 34 ~-0.041 35 > y = {{alias}}( 0.8, 4.0, 4.0 ) 36 ~-0.556 37 > y = {{alias}}( -0.5, 4.0, 2.0 ) 38 -Infinity 39 > y = {{alias}}( 1.5, 4.0, 2.0 ) 40 -Infinity 41 42 > y = {{alias}}( 0.5, -1.0, 0.5 ) 43 NaN 44 > y = {{alias}}( 0.5, 0.5, -1.0 ) 45 NaN 46 47 > y = {{alias}}( NaN, 1.0, 1.0 ) 48 NaN 49 > y = {{alias}}( 0.5, NaN, 1.0 ) 50 NaN 51 > y = {{alias}}( 0.5, 1.0, NaN ) 52 NaN 53 54 55 {{alias}}.factory( α, β ) 56 Returns a function for evaluating the natural logarithm of the probability 57 density function (PDF) of a beta distribution with first shape parameter `α` 58 and second shape parameter `β`. 59 60 Parameters 61 ---------- 62 α: number 63 First shape parameter. 64 65 β: number 66 Second shape parameter. 67 68 Returns 69 ------- 70 fcn: Function 71 Function to evaluate the natural logarithm of the PDF. 72 73 Examples 74 -------- 75 > var mylogpdf = {{alias}}.factory( 0.5, 0.5 ); 76 > var y = mylogpdf( 0.8 ) 77 ~-0.228 78 > y = mylogpdf( 0.3 ) 79 ~-0.364 80 81 See Also 82 -------- 83