\tan^{-1} \left(N + 1\right) - \tan^{-1} N\tan^{-1} \left(N + 1\right) - \tan^{-1} N(FPCore (N) :precision binary64 (- (atan (+ N 1.0)) (atan N)))
(FPCore (N) :precision binary64 (- (atan (+ N 1.0)) (atan N)))
double code(double N) {
return atan(N + 1.0) - atan(N);
}
double code(double N) {
return atan(N + 1.0) - atan(N);
}




Bits error versus N
Results
| Original | 15.3 |
|---|---|
| Target | 0.4 |
| Herbie | 15.3 |
Initial program 15.3
herbie shell --seed 2021027
(FPCore (N)
:name "2atan (example 3.5)"
:precision binary64
:herbie-target
(atan (/ 1.0 (+ 1.0 (* N (+ N 1.0)))))
(- (atan (+ N 1.0)) (atan N)))