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 r8282 = 1.0;
        double r8283 = atan2(1.0, 0.0);
        double r8284 = 4.0;
        double r8285 = r8283 / r8284;
        double r8286 = r8282 / r8285;
        double r8287 = f;
        double r8288 = r8285 * r8287;
        double r8289 = exp(r8288);
        double r8290 = -r8288;
        double r8291 = exp(r8290);
        double r8292 = r8289 + r8291;
        double r8293 = r8289 - r8291;
        double r8294 = r8292 / r8293;
        double r8295 = log(r8294);
        double r8296 = r8286 * r8295;
        double r8297 = -r8296;
        return r8297;
}