
(FPCore (N) :precision binary64 (- (log (+ N 1.0)) (log N)))
double code(double N) {
return log((N + 1.0)) - log(N);
}
real(8) function code(n)
real(8), intent (in) :: n
code = log((n + 1.0d0)) - log(n)
end function
public static double code(double N) {
return Math.log((N + 1.0)) - Math.log(N);
}
def code(N): return math.log((N + 1.0)) - math.log(N)
function code(N) return Float64(log(Float64(N + 1.0)) - log(N)) end
function tmp = code(N) tmp = log((N + 1.0)) - log(N); end
code[N_] := N[(N[Log[N[(N + 1.0), $MachinePrecision]], $MachinePrecision] - N[Log[N], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\log \left(N + 1\right) - \log N
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (N) :precision binary64 (- (log (+ N 1.0)) (log N)))
double code(double N) {
return log((N + 1.0)) - log(N);
}
real(8) function code(n)
real(8), intent (in) :: n
code = log((n + 1.0d0)) - log(n)
end function
public static double code(double N) {
return Math.log((N + 1.0)) - Math.log(N);
}
def code(N): return math.log((N + 1.0)) - math.log(N)
function code(N) return Float64(log(Float64(N + 1.0)) - log(N)) end
function tmp = code(N) tmp = log((N + 1.0)) - log(N); end
code[N_] := N[(N[Log[N[(N + 1.0), $MachinePrecision]], $MachinePrecision] - N[Log[N], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\log \left(N + 1\right) - \log N
\end{array}
(FPCore (N) :precision binary64 (if (<= (- (log (+ N 1.0)) (log N)) 2e-7) (+ (/ 1.0 N) (- (/ 0.3333333333333333 (pow N 3.0)) (/ 0.5 (* N N)))) (* 2.0 (- (log (sqrt (/ N (+ N 1.0))))))))
double code(double N) {
double tmp;
if ((log((N + 1.0)) - log(N)) <= 2e-7) {
tmp = (1.0 / N) + ((0.3333333333333333 / pow(N, 3.0)) - (0.5 / (N * N)));
} else {
tmp = 2.0 * -log(sqrt((N / (N + 1.0))));
}
return tmp;
}
real(8) function code(n)
real(8), intent (in) :: n
real(8) :: tmp
if ((log((n + 1.0d0)) - log(n)) <= 2d-7) then
tmp = (1.0d0 / n) + ((0.3333333333333333d0 / (n ** 3.0d0)) - (0.5d0 / (n * n)))
else
tmp = 2.0d0 * -log(sqrt((n / (n + 1.0d0))))
end if
code = tmp
end function
public static double code(double N) {
double tmp;
if ((Math.log((N + 1.0)) - Math.log(N)) <= 2e-7) {
tmp = (1.0 / N) + ((0.3333333333333333 / Math.pow(N, 3.0)) - (0.5 / (N * N)));
} else {
tmp = 2.0 * -Math.log(Math.sqrt((N / (N + 1.0))));
}
return tmp;
}
def code(N): tmp = 0 if (math.log((N + 1.0)) - math.log(N)) <= 2e-7: tmp = (1.0 / N) + ((0.3333333333333333 / math.pow(N, 3.0)) - (0.5 / (N * N))) else: tmp = 2.0 * -math.log(math.sqrt((N / (N + 1.0)))) return tmp
function code(N) tmp = 0.0 if (Float64(log(Float64(N + 1.0)) - log(N)) <= 2e-7) tmp = Float64(Float64(1.0 / N) + Float64(Float64(0.3333333333333333 / (N ^ 3.0)) - Float64(0.5 / Float64(N * N)))); else tmp = Float64(2.0 * Float64(-log(sqrt(Float64(N / Float64(N + 1.0)))))); end return tmp end
function tmp_2 = code(N) tmp = 0.0; if ((log((N + 1.0)) - log(N)) <= 2e-7) tmp = (1.0 / N) + ((0.3333333333333333 / (N ^ 3.0)) - (0.5 / (N * N))); else tmp = 2.0 * -log(sqrt((N / (N + 1.0)))); end tmp_2 = tmp; end
code[N_] := If[LessEqual[N[(N[Log[N[(N + 1.0), $MachinePrecision]], $MachinePrecision] - N[Log[N], $MachinePrecision]), $MachinePrecision], 2e-7], N[(N[(1.0 / N), $MachinePrecision] + N[(N[(0.3333333333333333 / N[Power[N, 3.0], $MachinePrecision]), $MachinePrecision] - N[(0.5 / N[(N * N), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(2.0 * (-N[Log[N[Sqrt[N[(N / N[(N + 1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision])), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\log \left(N + 1\right) - \log N \leq 2 \cdot 10^{-7}:\\
\;\;\;\;\frac{1}{N} + \left(\frac{0.3333333333333333}{{N}^{3}} - \frac{0.5}{N \cdot N}\right)\\
\mathbf{else}:\\
\;\;\;\;2 \cdot \left(-\log \left(\sqrt{\frac{N}{N + 1}}\right)\right)\\
\end{array}
\end{array}
if (-.f64 (log.f64 (+.f64 N 1)) (log.f64 N)) < 1.9999999999999999e-7Initial program 6.9%
+-commutative6.9%
log1p-def6.9%
Simplified6.9%
Taylor expanded in N around inf 100.0%
associate--l+100.0%
associate-*r/100.0%
metadata-eval100.0%
associate-*r/100.0%
metadata-eval100.0%
unpow2100.0%
Simplified100.0%
if 1.9999999999999999e-7 < (-.f64 (log.f64 (+.f64 N 1)) (log.f64 N)) Initial program 99.9%
+-commutative99.9%
log1p-def99.9%
Simplified99.9%
log1p-udef99.9%
diff-log99.9%
+-commutative99.9%
Applied egg-rr99.9%
clear-num99.9%
log-div99.9%
metadata-eval99.9%
Applied egg-rr99.9%
neg-sub099.9%
Simplified99.9%
add-sqr-sqrt99.9%
log-prod100.0%
Applied egg-rr100.0%
count-2100.0%
Simplified100.0%
Final simplification100.0%
(FPCore (N) :precision binary64 (if (<= (- (log (+ N 1.0)) (log N)) 2e-7) (+ (/ 1.0 N) (- (/ 0.3333333333333333 (pow N 3.0)) (/ 0.5 (* N N)))) (- (log (/ N (+ N 1.0))))))
double code(double N) {
double tmp;
if ((log((N + 1.0)) - log(N)) <= 2e-7) {
tmp = (1.0 / N) + ((0.3333333333333333 / pow(N, 3.0)) - (0.5 / (N * N)));
} else {
tmp = -log((N / (N + 1.0)));
}
return tmp;
}
real(8) function code(n)
real(8), intent (in) :: n
real(8) :: tmp
if ((log((n + 1.0d0)) - log(n)) <= 2d-7) then
tmp = (1.0d0 / n) + ((0.3333333333333333d0 / (n ** 3.0d0)) - (0.5d0 / (n * n)))
else
tmp = -log((n / (n + 1.0d0)))
end if
code = tmp
end function
public static double code(double N) {
double tmp;
if ((Math.log((N + 1.0)) - Math.log(N)) <= 2e-7) {
tmp = (1.0 / N) + ((0.3333333333333333 / Math.pow(N, 3.0)) - (0.5 / (N * N)));
} else {
tmp = -Math.log((N / (N + 1.0)));
}
return tmp;
}
def code(N): tmp = 0 if (math.log((N + 1.0)) - math.log(N)) <= 2e-7: tmp = (1.0 / N) + ((0.3333333333333333 / math.pow(N, 3.0)) - (0.5 / (N * N))) else: tmp = -math.log((N / (N + 1.0))) return tmp
function code(N) tmp = 0.0 if (Float64(log(Float64(N + 1.0)) - log(N)) <= 2e-7) tmp = Float64(Float64(1.0 / N) + Float64(Float64(0.3333333333333333 / (N ^ 3.0)) - Float64(0.5 / Float64(N * N)))); else tmp = Float64(-log(Float64(N / Float64(N + 1.0)))); end return tmp end
function tmp_2 = code(N) tmp = 0.0; if ((log((N + 1.0)) - log(N)) <= 2e-7) tmp = (1.0 / N) + ((0.3333333333333333 / (N ^ 3.0)) - (0.5 / (N * N))); else tmp = -log((N / (N + 1.0))); end tmp_2 = tmp; end
code[N_] := If[LessEqual[N[(N[Log[N[(N + 1.0), $MachinePrecision]], $MachinePrecision] - N[Log[N], $MachinePrecision]), $MachinePrecision], 2e-7], N[(N[(1.0 / N), $MachinePrecision] + N[(N[(0.3333333333333333 / N[Power[N, 3.0], $MachinePrecision]), $MachinePrecision] - N[(0.5 / N[(N * N), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], (-N[Log[N[(N / N[(N + 1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision])]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\log \left(N + 1\right) - \log N \leq 2 \cdot 10^{-7}:\\
\;\;\;\;\frac{1}{N} + \left(\frac{0.3333333333333333}{{N}^{3}} - \frac{0.5}{N \cdot N}\right)\\
\mathbf{else}:\\
\;\;\;\;-\log \left(\frac{N}{N + 1}\right)\\
\end{array}
\end{array}
if (-.f64 (log.f64 (+.f64 N 1)) (log.f64 N)) < 1.9999999999999999e-7Initial program 6.9%
+-commutative6.9%
log1p-def6.9%
Simplified6.9%
Taylor expanded in N around inf 100.0%
associate--l+100.0%
associate-*r/100.0%
metadata-eval100.0%
associate-*r/100.0%
metadata-eval100.0%
unpow2100.0%
Simplified100.0%
if 1.9999999999999999e-7 < (-.f64 (log.f64 (+.f64 N 1)) (log.f64 N)) Initial program 99.9%
+-commutative99.9%
log1p-def99.9%
Simplified99.9%
log1p-udef99.9%
diff-log99.9%
+-commutative99.9%
Applied egg-rr99.9%
clear-num99.9%
log-div99.9%
metadata-eval99.9%
Applied egg-rr99.9%
neg-sub099.9%
Simplified99.9%
Final simplification100.0%
(FPCore (N) :precision binary64 (if (<= N 240000.0) (- (log (/ N (+ N 1.0)))) (- (/ 1.0 N) (/ (/ 0.5 N) N))))
double code(double N) {
double tmp;
if (N <= 240000.0) {
tmp = -log((N / (N + 1.0)));
} else {
tmp = (1.0 / N) - ((0.5 / N) / N);
}
return tmp;
}
real(8) function code(n)
real(8), intent (in) :: n
real(8) :: tmp
if (n <= 240000.0d0) then
tmp = -log((n / (n + 1.0d0)))
else
tmp = (1.0d0 / n) - ((0.5d0 / n) / n)
end if
code = tmp
end function
public static double code(double N) {
double tmp;
if (N <= 240000.0) {
tmp = -Math.log((N / (N + 1.0)));
} else {
tmp = (1.0 / N) - ((0.5 / N) / N);
}
return tmp;
}
def code(N): tmp = 0 if N <= 240000.0: tmp = -math.log((N / (N + 1.0))) else: tmp = (1.0 / N) - ((0.5 / N) / N) return tmp
function code(N) tmp = 0.0 if (N <= 240000.0) tmp = Float64(-log(Float64(N / Float64(N + 1.0)))); else tmp = Float64(Float64(1.0 / N) - Float64(Float64(0.5 / N) / N)); end return tmp end
function tmp_2 = code(N) tmp = 0.0; if (N <= 240000.0) tmp = -log((N / (N + 1.0))); else tmp = (1.0 / N) - ((0.5 / N) / N); end tmp_2 = tmp; end
code[N_] := If[LessEqual[N, 240000.0], (-N[Log[N[(N / N[(N + 1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), N[(N[(1.0 / N), $MachinePrecision] - N[(N[(0.5 / N), $MachinePrecision] / N), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;N \leq 240000:\\
\;\;\;\;-\log \left(\frac{N}{N + 1}\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{N} - \frac{\frac{0.5}{N}}{N}\\
\end{array}
\end{array}
if N < 2.4e5Initial program 99.9%
+-commutative99.9%
log1p-def99.9%
Simplified99.9%
log1p-udef99.9%
diff-log99.9%
+-commutative99.9%
Applied egg-rr99.9%
clear-num99.9%
log-div99.9%
metadata-eval99.9%
Applied egg-rr99.9%
neg-sub099.9%
Simplified99.9%
if 2.4e5 < N Initial program 6.9%
+-commutative6.9%
log1p-def6.9%
Simplified6.9%
Taylor expanded in N around inf 99.8%
associate-*r/99.8%
metadata-eval99.8%
unpow299.8%
associate-/r*99.8%
Simplified99.8%
Final simplification99.9%
(FPCore (N) :precision binary64 (if (<= N 205000.0) (log (/ (+ N 1.0) N)) (- (/ 1.0 N) (/ (/ 0.5 N) N))))
double code(double N) {
double tmp;
if (N <= 205000.0) {
tmp = log(((N + 1.0) / N));
} else {
tmp = (1.0 / N) - ((0.5 / N) / N);
}
return tmp;
}
real(8) function code(n)
real(8), intent (in) :: n
real(8) :: tmp
if (n <= 205000.0d0) then
tmp = log(((n + 1.0d0) / n))
else
tmp = (1.0d0 / n) - ((0.5d0 / n) / n)
end if
code = tmp
end function
public static double code(double N) {
double tmp;
if (N <= 205000.0) {
tmp = Math.log(((N + 1.0) / N));
} else {
tmp = (1.0 / N) - ((0.5 / N) / N);
}
return tmp;
}
def code(N): tmp = 0 if N <= 205000.0: tmp = math.log(((N + 1.0) / N)) else: tmp = (1.0 / N) - ((0.5 / N) / N) return tmp
function code(N) tmp = 0.0 if (N <= 205000.0) tmp = log(Float64(Float64(N + 1.0) / N)); else tmp = Float64(Float64(1.0 / N) - Float64(Float64(0.5 / N) / N)); end return tmp end
function tmp_2 = code(N) tmp = 0.0; if (N <= 205000.0) tmp = log(((N + 1.0) / N)); else tmp = (1.0 / N) - ((0.5 / N) / N); end tmp_2 = tmp; end
code[N_] := If[LessEqual[N, 205000.0], N[Log[N[(N[(N + 1.0), $MachinePrecision] / N), $MachinePrecision]], $MachinePrecision], N[(N[(1.0 / N), $MachinePrecision] - N[(N[(0.5 / N), $MachinePrecision] / N), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;N \leq 205000:\\
\;\;\;\;\log \left(\frac{N + 1}{N}\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{N} - \frac{\frac{0.5}{N}}{N}\\
\end{array}
\end{array}
if N < 205000Initial program 99.9%
+-commutative99.9%
log1p-def99.9%
Simplified99.9%
log1p-udef99.9%
diff-log99.9%
+-commutative99.9%
Applied egg-rr99.9%
if 205000 < N Initial program 6.9%
+-commutative6.9%
log1p-def6.9%
Simplified6.9%
Taylor expanded in N around inf 99.8%
associate-*r/99.8%
metadata-eval99.8%
unpow299.8%
associate-/r*99.8%
Simplified99.8%
Final simplification99.9%
(FPCore (N) :precision binary64 (if (<= N 0.9) (- N (log N)) (- (/ 1.0 N) (/ (/ 0.5 N) N))))
double code(double N) {
double tmp;
if (N <= 0.9) {
tmp = N - log(N);
} else {
tmp = (1.0 / N) - ((0.5 / N) / N);
}
return tmp;
}
real(8) function code(n)
real(8), intent (in) :: n
real(8) :: tmp
if (n <= 0.9d0) then
tmp = n - log(n)
else
tmp = (1.0d0 / n) - ((0.5d0 / n) / n)
end if
code = tmp
end function
public static double code(double N) {
double tmp;
if (N <= 0.9) {
tmp = N - Math.log(N);
} else {
tmp = (1.0 / N) - ((0.5 / N) / N);
}
return tmp;
}
def code(N): tmp = 0 if N <= 0.9: tmp = N - math.log(N) else: tmp = (1.0 / N) - ((0.5 / N) / N) return tmp
function code(N) tmp = 0.0 if (N <= 0.9) tmp = Float64(N - log(N)); else tmp = Float64(Float64(1.0 / N) - Float64(Float64(0.5 / N) / N)); end return tmp end
function tmp_2 = code(N) tmp = 0.0; if (N <= 0.9) tmp = N - log(N); else tmp = (1.0 / N) - ((0.5 / N) / N); end tmp_2 = tmp; end
code[N_] := If[LessEqual[N, 0.9], N[(N - N[Log[N], $MachinePrecision]), $MachinePrecision], N[(N[(1.0 / N), $MachinePrecision] - N[(N[(0.5 / N), $MachinePrecision] / N), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;N \leq 0.9:\\
\;\;\;\;N - \log N\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{N} - \frac{\frac{0.5}{N}}{N}\\
\end{array}
\end{array}
if N < 0.900000000000000022Initial program 100.0%
+-commutative100.0%
log1p-def100.0%
Simplified100.0%
Taylor expanded in N around 0 99.5%
neg-mul-199.5%
unsub-neg99.5%
Simplified99.5%
if 0.900000000000000022 < N Initial program 7.6%
+-commutative7.6%
log1p-def7.6%
Simplified7.6%
Taylor expanded in N around inf 99.3%
associate-*r/99.3%
metadata-eval99.3%
unpow299.3%
associate-/r*99.3%
Simplified99.3%
Final simplification99.4%
(FPCore (N) :precision binary64 (if (<= N 0.65) (- (log N)) (- (/ 1.0 N) (/ (/ 0.5 N) N))))
double code(double N) {
double tmp;
if (N <= 0.65) {
tmp = -log(N);
} else {
tmp = (1.0 / N) - ((0.5 / N) / N);
}
return tmp;
}
real(8) function code(n)
real(8), intent (in) :: n
real(8) :: tmp
if (n <= 0.65d0) then
tmp = -log(n)
else
tmp = (1.0d0 / n) - ((0.5d0 / n) / n)
end if
code = tmp
end function
public static double code(double N) {
double tmp;
if (N <= 0.65) {
tmp = -Math.log(N);
} else {
tmp = (1.0 / N) - ((0.5 / N) / N);
}
return tmp;
}
def code(N): tmp = 0 if N <= 0.65: tmp = -math.log(N) else: tmp = (1.0 / N) - ((0.5 / N) / N) return tmp
function code(N) tmp = 0.0 if (N <= 0.65) tmp = Float64(-log(N)); else tmp = Float64(Float64(1.0 / N) - Float64(Float64(0.5 / N) / N)); end return tmp end
function tmp_2 = code(N) tmp = 0.0; if (N <= 0.65) tmp = -log(N); else tmp = (1.0 / N) - ((0.5 / N) / N); end tmp_2 = tmp; end
code[N_] := If[LessEqual[N, 0.65], (-N[Log[N], $MachinePrecision]), N[(N[(1.0 / N), $MachinePrecision] - N[(N[(0.5 / N), $MachinePrecision] / N), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;N \leq 0.65:\\
\;\;\;\;-\log N\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{N} - \frac{\frac{0.5}{N}}{N}\\
\end{array}
\end{array}
if N < 0.650000000000000022Initial program 100.0%
+-commutative100.0%
log1p-def100.0%
Simplified100.0%
Taylor expanded in N around 0 98.1%
neg-mul-198.1%
Simplified98.1%
if 0.650000000000000022 < N Initial program 7.6%
+-commutative7.6%
log1p-def7.6%
Simplified7.6%
Taylor expanded in N around inf 99.3%
associate-*r/99.3%
metadata-eval99.3%
unpow299.3%
associate-/r*99.3%
Simplified99.3%
Final simplification98.6%
(FPCore (N) :precision binary64 (/ 1.0 N))
double code(double N) {
return 1.0 / N;
}
real(8) function code(n)
real(8), intent (in) :: n
code = 1.0d0 / n
end function
public static double code(double N) {
return 1.0 / N;
}
def code(N): return 1.0 / N
function code(N) return Float64(1.0 / N) end
function tmp = code(N) tmp = 1.0 / N; end
code[N_] := N[(1.0 / N), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{N}
\end{array}
Initial program 59.2%
+-commutative59.2%
log1p-def59.2%
Simplified59.2%
Taylor expanded in N around inf 46.4%
Final simplification46.4%
(FPCore (N) :precision binary64 -0.5)
double code(double N) {
return -0.5;
}
real(8) function code(n)
real(8), intent (in) :: n
code = -0.5d0
end function
public static double code(double N) {
return -0.5;
}
def code(N): return -0.5
function code(N) return -0.5 end
function tmp = code(N) tmp = -0.5; end
code[N_] := -0.5
\begin{array}{l}
\\
-0.5
\end{array}
Initial program 59.2%
+-commutative59.2%
log1p-def59.2%
Simplified59.2%
Taylor expanded in N around inf 44.3%
associate-*r/44.3%
metadata-eval44.3%
unpow244.3%
associate-/r*44.3%
Simplified44.3%
sub-div44.3%
div-inv44.3%
cancel-sign-sub-inv44.3%
metadata-eval44.3%
add-exp-log44.3%
neg-log44.3%
add-sqr-sqrt0.5%
sqrt-unprod1.5%
sqr-neg1.5%
unpow21.5%
unpow21.5%
sqrt-prod1.0%
add-sqr-sqrt4.1%
add-exp-log4.1%
Applied egg-rr4.1%
*-commutative4.1%
Simplified4.1%
Taylor expanded in N around inf 1.9%
Final simplification1.9%
herbie shell --seed 2023273
(FPCore (N)
:name "2log (problem 3.3.6)"
:precision binary64
(- (log (+ N 1.0)) (log N)))