Cannot sample enough valid points. (more)

\[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right)\]
-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right)
double f(double f) {
        double r8026 = 1.0;
        double r8027 = atan2(1.0, 0.0);
        double r8028 = 4.0;
        double r8029 = r8027 / r8028;
        double r8030 = r8026 / r8029;
        double r8031 = f;
        double r8032 = r8029 * r8031;
        double r8033 = exp(r8032);
        double r8034 = -r8032;
        double r8035 = exp(r8034);
        double r8036 = r8033 + r8035;
        double r8037 = r8033 - r8035;
        double r8038 = r8036 / r8037;
        double r8039 = log(r8038);
        double r8040 = r8030 * r8039;
        double r8041 = -r8040;
        return r8041;
}