System.Random.MWC.Distributions:gamma from mwc-random-0.13.3.2

Average Error: 0.1 → 0.1

Time: 12.0s

Precision: binary64

Cost: 7232

Math

\[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right) \]

↓

\[x \cdot 0.5 + \left(\left(y + y \cdot \log z\right) - y \cdot z\right) \]

FPCore

(FPCore (x y z) :precision binary64 (+ (* x 0.5) (* y (+ (- 1.0 z) (log z)))))

↓

(FPCore (x y z)
 :precision binary64
 (+ (* x 0.5) (- (+ y (* y (log z))) (* y z))))

C

double code(double x, double y, double z) {
	return (x * 0.5) + (y * ((1.0 - z) + log(z)));
}

↓

double code(double x, double y, double z) {
	return (x * 0.5) + ((y + (y * log(z))) - (y * z));
}

Fortran

real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = (x * 0.5d0) + (y * ((1.0d0 - z) + log(z)))
end function

↓

real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = (x * 0.5d0) + ((y + (y * log(z))) - (y * z))
end function

Java

public static double code(double x, double y, double z) {
	return (x * 0.5) + (y * ((1.0 - z) + Math.log(z)));
}

↓

public static double code(double x, double y, double z) {
	return (x * 0.5) + ((y + (y * Math.log(z))) - (y * z));
}

Python

def code(x, y, z):
	return (x * 0.5) + (y * ((1.0 - z) + math.log(z)))

↓

def code(x, y, z):
	return (x * 0.5) + ((y + (y * math.log(z))) - (y * z))

Julia

function code(x, y, z)
	return Float64(Float64(x * 0.5) + Float64(y * Float64(Float64(1.0 - z) + log(z))))
end

↓

function code(x, y, z)
	return Float64(Float64(x * 0.5) + Float64(Float64(y + Float64(y * log(z))) - Float64(y * z)))
end

MATLAB

function tmp = code(x, y, z)
	tmp = (x * 0.5) + (y * ((1.0 - z) + log(z)));
end

↓

function tmp = code(x, y, z)
	tmp = (x * 0.5) + ((y + (y * log(z))) - (y * z));
end

Wolfram

code[x_, y_, z_] := N[(N[(x * 0.5), $MachinePrecision] + N[(y * N[(N[(1.0 - z), $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]

↓

code[x_, y_, z_] := N[(N[(x * 0.5), $MachinePrecision] + N[(N[(y + N[(y * N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(y * z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]

Target

Original	0.1
Target	0.1
Herbie	0.1

\[\left(y + 0.5 \cdot x\right) - y \cdot \left(z - \log z\right) \]

Derivation

1. Initial program 0.1

   \[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right) \]

2. Applied egg-rr 0.1

   \[\leadsto x \cdot 0.5 + \color{blue}{\left(\left(y \cdot \log z + y\right) + y \cdot \left(-z\right)\right)} \]

3. Final simplification 0.1

   \[\leadsto x \cdot 0.5 + \left(\left(y + y \cdot \log z\right) - y \cdot z\right) \]

Alternatives

Alternative 1
Error	15.5
Cost	7248

\[\begin{array}{l} t_0 := y \cdot \left(\log z + 1\right)\\ \mathbf{if}\;y \leq -5.2 \cdot 10^{+131}:\\ \;\;\;\;t_0\\ \mathbf{elif}\;y \leq 1.15 \cdot 10^{+61}:\\ \;\;\;\;x \cdot 0.5 - y \cdot z\\ \mathbf{elif}\;y \leq 2.9 \cdot 10^{+147}:\\ \;\;\;\;y + y \cdot \log z\\ \mathbf{elif}\;y \leq 1.35 \cdot 10^{+157}:\\ \;\;\;\;y \cdot \left(-z\right)\\ \mathbf{else}:\\ \;\;\;\;t_0\\ \end{array} \]

Alternative 2
Error	11.5
Cost	7113

\[\begin{array}{l} \mathbf{if}\;y \leq -1.35 \cdot 10^{+129} \lor \neg \left(y \leq 280000000\right):\\ \;\;\;\;y \cdot \left(\left(\log z + 1\right) - z\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot 0.5 - y \cdot z\\ \end{array} \]

Alternative 3
Error	1.3
Cost	7108

\[\begin{array}{l} \mathbf{if}\;z \leq 10^{-16}:\\ \;\;\;\;y \cdot \log z + \left(x \cdot 0.5 + y\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot 0.5 + \left(y - y \cdot z\right)\\ \end{array} \]

Alternative 4
Error	0.1
Cost	7104

\[x \cdot 0.5 + y \cdot \left(\log z + \left(1 - z\right)\right) \]

Alternative 5
Error	15.4
Cost	6985

\[\begin{array}{l} \mathbf{if}\;y \leq -1.9 \cdot 10^{+130} \lor \neg \left(y \leq 2 \cdot 10^{+62}\right):\\ \;\;\;\;y \cdot \left(\log z + 1\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot 0.5 - y \cdot z\\ \end{array} \]

Alternative 6
Error	28.2
Cost	520

\[\begin{array}{l} \mathbf{if}\;x \leq -5 \cdot 10^{-39}:\\ \;\;\;\;x \cdot 0.5\\ \mathbf{elif}\;x \leq 1.5 \cdot 10^{-58}:\\ \;\;\;\;y \cdot \left(-z\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot 0.5\\ \end{array} \]

Alternative 7
Error	18.1
Cost	448

\[x \cdot 0.5 - y \cdot z \]

Alternative 8
Error	34.9
Cost	192

\[x \cdot 0.5 \]

Alternative 9
Error	62.7
Cost	64

\[y \]

Reproduce

herbie shell --seed 2023027 
(FPCore (x y z)
  :name "System.Random.MWC.Distributions:gamma from mwc-random-0.13.3.2"
  :precision binary64

  :herbie-target
  (- (+ y (* 0.5 x)) (* y (- z (log z))))

  (+ (* x 0.5) (* y (+ (- 1.0 z) (log z)))))