stat_buffer.h
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00001 // *****************************************************************************
00002 //
00003 // Copyright (c) 2014, Southwest Research Institute® (SwRI®)
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00005 //
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00010 //     * Redistributions in binary form must reproduce the above copyright
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00029 
00030 #ifndef MATH_UTIL_STAT_BUFFER_H_
00031 #define MATH_UTIL_STAT_BUFFER_H_
00032 
00033 #ifndef PI
00034 #define PI 3.14159265358979
00035 #endif
00036 
00037 #include <cmath>
00038 #include <algorithm>
00039 
00040 #include <swri_math_util/generic_ring_buffer.h>
00041 
00042 namespace swri_math_util
00043 {
00044   template <class T>
00045   class StatBuffer: public GenRingBuffer<T>
00046   {
00047   public:
00048     void modifyBufferSize(int NumElements)  // moved from private 04/02/2008 JJC
00049     {
00050       this->realloc_mem(NumElements);
00051     }
00052 
00053     StatBuffer()
00054     {
00055       this->modifyBufferSize(30);
00056     }
00057 
00058     explicit StatBuffer(int NumElements)
00059     {
00060       this->modifyBufferSize(NumElements);
00061     }
00062 
00063     ~StatBuffer()
00064     {
00065       this->modifyBufferSize(0);
00066     }
00067 
00068     bool UpdateStats()
00069     {
00070       return this->computeStats();
00071     }
00072 
00073     bool UpdateDiffStats()
00074     {
00075       return this->computeDiffStats();
00076     }
00077 
00078     T reportDiffMean()
00079     {
00080       return RetainedDiffStats.mean;
00081     }
00082 
00083     T reportDiffMedian()
00084     {
00085       return RetainedDiffStats.median;
00086     }
00087 
00088     T reportDiffMin()
00089     {
00090       return RetainedDiffStats.min;
00091     }
00092 
00093     T reportDiffMax()
00094     {
00095       return RetainedDiffStats.max;
00096     }
00097 
00098     T reportMean()
00099     {
00100       return RetainedStats.mean;
00101     }
00102 
00103     // Computes the mean of the last NumToAvg items in the buffer
00104     T reportPartialMean(int NumToAvg)
00105     {
00106       return this->computeMean(NumToAvg);
00107     }
00108 
00109     T reportMedian()
00110     {
00111       return RetainedStats.median;
00112     }
00113 
00114     T reportMin()
00115     {
00116       return RetainedStats.min;
00117     }
00118 
00119     T reportMax()
00120     {
00121       return RetainedStats.max;
00122     }
00123     T reportStd()
00124     {
00125       return RetainedStats.std;
00126     }
00127 
00128     T reportVar()
00129     {
00130       return RetainedStats.variance;
00131     }
00132     T reportRetainedStats()
00133     {
00134       return RetainedStats;
00135     }
00136 
00137   private:
00138     typedef struct
00139     {
00140       T mean;
00141       T min;
00142       T max;
00143       T median;
00144       T std;
00145       T variance;
00146     } StatPack;
00147 
00148     StatPack RetainedStats;
00149     StatPack RetainedDiffStats;
00150 
00151     T computeMean(int NumToAvg)
00152     {
00153       int NumElems = this->size();
00154       if (NumElems <= 0) return (T)(0.0);
00155       T CurVal = *this->getTail(0);
00156       T sum = 0;
00157       NumToAvg = std::min(NumToAvg, NumElems);
00158       for (int i = 0; i < NumToAvg; ++i)
00159       {
00160         CurVal = *this->getTail(i);
00161         sum += CurVal;
00162       }
00163       T mean = sum/((T)NumToAvg);
00164       return mean;
00165     }
00166 
00167     bool computeStats()
00168     {
00169       int NumElems = this->size();
00170       if (NumElems <= 0) return false;
00171 
00172       T sum = 0;
00173       T &min = RetainedStats.min;
00174       T &max = RetainedStats.max;
00175       T &mean = RetainedStats.mean;
00176       T &median = RetainedStats.median;
00177       T &std = RetainedStats.std;
00178       T &var = RetainedStats.variance;
00179 
00180       T CurVal = *this->get(0);
00181       sum += CurVal;
00182       min = CurVal;
00183       max = CurVal;
00184       mean = CurVal;
00185       median = CurVal;
00186       std = 0;
00187       var = std*std;
00188 
00189       // compute mean, min and max
00190       for (int i = 1; i < NumElems; i++)
00191       {
00192         CurVal = *this->get(i);
00193         sum += CurVal;
00194         if (CurVal > max) max = CurVal;
00195         else if (CurVal < min) min = CurVal;
00196       }
00197       mean = sum/((T)NumElems);
00198       sum = 0;
00199 
00200       // compute
00201       if (NumElems > 1)
00202       {
00203         T *vec1 = new T[NumElems];  // for median calculation
00204         for (int i = 0; i < NumElems; i++)
00205         {
00206           CurVal = *this->get(i);
00207           sum += (CurVal-mean)*(CurVal-mean);
00208           vec1[i] = CurVal;  // for median calculation
00209         }
00210         std=(T)sqrt(static_cast<double>(sum/(NumElems-1)));
00211         var = std*std;
00212 
00213         // Compute Median
00214         std::sort(vec1, vec1+NumElems);  // first sort the data
00215         if (NumElems % 2 == 0)
00216         {
00217           median = (vec1[NumElems/2-1] + vec1[NumElems/2])/2;
00218         }
00219         else
00220         {
00221           median = vec1[NumElems/2];
00222         }
00223         if (NumElems <= 1)
00224         {
00225           delete vec1;
00226         }
00227         else
00228         {
00229           delete [] vec1;
00230         }
00231       }
00232 
00233       return true;
00234     }
00235 
00236     bool computeDiffStats()
00237     {
00238       int NumElems = this->size();
00239       if (NumElems <= 1) return false;
00240 
00241       T sum    = 0;
00242       T &min    = RetainedDiffStats.min;
00243       T &max    = RetainedDiffStats.max;
00244       T &mean    = RetainedDiffStats.mean;
00245       T &median  = RetainedDiffStats.median;
00246 
00247       T *vec1 = new T[NumElems];
00248 
00249       T CurVal1 = *this->get(0);
00250       T CurVal2 = *this->get(1);
00251       T CVDiff = CurVal2-CurVal1;
00252 
00253       vec1[0] = CVDiff;
00254 
00255       sum += CVDiff;
00256       min = CVDiff;
00257       max = CVDiff;
00258       mean = CVDiff;
00259       median = CVDiff;
00260       for (int i = 1; i < NumElems-1; i++)
00261       {
00262         CurVal1 = *this->get(i);
00263         CurVal2 = *this->get(i+1);
00264         CVDiff = CurVal2-CurVal1;
00265         vec1[i] = CVDiff;
00266         sum += CVDiff;
00267         if (CVDiff > max) max = CVDiff;
00268         else if (CVDiff < min) min = CVDiff;
00269       }
00270       mean = sum/((T)NumElems);
00271 
00272       NumElems--;  // we put in one fewer than NumElems into the vector
00273       std::sort(vec1, vec1+NumElems);  // first sort the data
00274       if (NumElems % 2 == 0)
00275       {
00276         median = (vec1[NumElems/2-1] + vec1[NumElems/2])/2;
00277       }
00278       else
00279       {
00280         median = vec1[NumElems/2];
00281       }
00282 
00283       delete [] vec1;
00284 
00285       return true;
00286     }
00287   };
00288 }
00289 
00290 
00291 #endif  // MATH_UTIL_STAT_BUFFER_H_


swri_math_util
Author(s): Marc Alban
autogenerated on Tue Oct 3 2017 03:19:18