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 r121 = 1.0;
        double r122 = atan2(1.0, 0.0);
        double r123 = 4.0;
        double r124 = r122 / r123;
        double r125 = r121 / r124;
        double r126 = f;
        double r127 = r124 * r126;
        double r128 = exp(r127);
        double r129 = -r127;
        double r130 = exp(r129);
        double r131 = r128 + r130;
        double r132 = r128 - r130;
        double r133 = r131 / r132;
        double r134 = log(r133);
        double r135 = r125 * r134;
        double r136 = -r135;
        return r136;
}