Function stair_activate

yolo_detector/darknet_opt/src/activations.h:19–24

#endif

static inline float stair_activate(float x)
{
    int n = floor(x);
    if (n%2 == 0) return floor(x/2.);
    else return (x - n) + floor(x/2.);
}
static inline float hardtan_activate(float x)
{
    if (x < -1) return -1;