\frac{\frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)}}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1}\begin{array}{l}
\mathbf{if}\;i \le 218.0369401643284845704329200088977813721:\\
\;\;\;\;\frac{i \cdot i}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)}\\
\mathbf{else}:\\
\;\;\;\;0.00390625 \cdot \frac{1}{{i}^{4}} + \left(0.015625 \cdot \frac{1}{{i}^{2}} + 0.0625\right)\\
\end{array}double f(double i) {
double r47817 = i;
double r47818 = r47817 * r47817;
double r47819 = r47818 * r47818;
double r47820 = 2.0;
double r47821 = r47820 * r47817;
double r47822 = r47821 * r47821;
double r47823 = r47819 / r47822;
double r47824 = 1.0;
double r47825 = r47822 - r47824;
double r47826 = r47823 / r47825;
return r47826;
}
double f(double i) {
double r47827 = i;
double r47828 = 218.03694016432848;
bool r47829 = r47827 <= r47828;
double r47830 = r47827 * r47827;
double r47831 = 2.0;
double r47832 = r47831 * r47827;
double r47833 = r47832 * r47832;
double r47834 = 1.0;
double r47835 = r47833 - r47834;
double r47836 = r47831 * r47831;
double r47837 = r47835 * r47836;
double r47838 = r47830 / r47837;
double r47839 = 0.00390625;
double r47840 = 1.0;
double r47841 = 4.0;
double r47842 = pow(r47827, r47841);
double r47843 = r47840 / r47842;
double r47844 = r47839 * r47843;
double r47845 = 0.015625;
double r47846 = 2.0;
double r47847 = pow(r47827, r47846);
double r47848 = r47840 / r47847;
double r47849 = r47845 * r47848;
double r47850 = 0.0625;
double r47851 = r47849 + r47850;
double r47852 = r47844 + r47851;
double r47853 = r47829 ? r47838 : r47852;
return r47853;
}



Bits error versus i
Results
if i < 218.03694016432848Initial program 44.7
Simplified0.0
if 218.03694016432848 < i Initial program 49.1
Simplified33.0
Taylor expanded around inf 0.0
Final simplification0.0
herbie shell --seed 2019294
(FPCore (i)
:name "Octave 3.8, jcobi/4, as called"
:precision binary64
:pre (and (> i 0.0))
(/ (/ (* (* i i) (* i i)) (* (* 2 i) (* 2 i))) (- (* (* 2 i) (* 2 i)) 1)))