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 r131 = 1.0;
        double r132 = atan2(1.0, 0.0);
        double r133 = 4.0;
        double r134 = r132 / r133;
        double r135 = r131 / r134;
        double r136 = f;
        double r137 = r134 * r136;
        double r138 = exp(r137);
        double r139 = -r137;
        double r140 = exp(r139);
        double r141 = r138 + r140;
        double r142 = r138 - r140;
        double r143 = r141 / r142;
        double r144 = log(r143);
        double r145 = r135 * r144;
        double r146 = -r145;
        return r146;
}