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 r8079 = 1.0;
        double r8080 = atan2(1.0, 0.0);
        double r8081 = 4.0;
        double r8082 = r8080 / r8081;
        double r8083 = r8079 / r8082;
        double r8084 = f;
        double r8085 = r8082 * r8084;
        double r8086 = exp(r8085);
        double r8087 = -r8085;
        double r8088 = exp(r8087);
        double r8089 = r8086 + r8088;
        double r8090 = r8086 - r8088;
        double r8091 = r8089 / r8090;
        double r8092 = log(r8091);
        double r8093 = r8083 * r8092;
        double r8094 = -r8093;
        return r8094;
}