dither.h
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00034 
00037 #ifndef CTRL_TOOLBOX_DITHER_H
00038 #define CTRL_TOOLBOX_DITHER_H
00039 
00040 #include <cstdlib>
00041 #include <ctime>
00042 #include <math.h>
00043 #include <ros/ros.h>
00044 
00045 namespace control_toolbox {
00046 
00047 /***************************************************/
00057 class Dither
00058 {
00059 public:
00060 
00061   Dither();
00062 
00066   ~Dither();
00067 
00072   double update();
00073 
00074    /*
00075    *\brief Dither gets an amplitude, must be >0 to initialize
00076    *
00077    *\param amplitude Amplitude of white noise output
00078    *\param seed Random seed for white noise
00079    */
00080   bool init(const double &amplitude, const double &seed)
00081   {
00082     if (amplitude < 0.0)
00083     {
00084       ROS_ERROR("Dither amplitude not set properly. Amplitude must be >0.");
00085       return false;
00086     }
00087     
00088     amplitude_ = amplitude;
00089 
00090     // Somewhat mimics the old code.  A given seed gives a
00091     // reproducible sequence of random numbers, and that's what
00092     // matters.
00093     unsigned long s = (unsigned long)seed;
00094     seed_[0] = (s) ^ 45213;
00095     seed_[1] = (s >> 16) ^ 39204;
00096     seed_[2] = (s >> 32) ^ 5598;
00097     
00098     return true;
00099   }
00100 
00101 
00102 private:
00103   double amplitude_;   
00104   double saved_value_;
00105   bool has_saved_value_;
00106   double s_;
00107   double x_;
00108   unsigned short seed_[3];
00109 };
00110 }
00111 
00112 #endif


control_toolbox
Author(s): Melonee Wise, Sachin Chitta, John Hsu
autogenerated on Fri Jan 3 2014 11:41:22