+ version 0.1.06

+ dynamic internal buffers + replace sorted buffer with "indirection buffer" + bubble sort + flag (faster)

Author: RobTillaart

libraries/RunningMedian/RunningMedian.cpp

@@ -11,7 +11,7 @@
 // 0.1.03 - 2013-09-30 added _sorted flag, minor refactor
 // 0.1.04 - 2013-10-17 added getAverage(uint8_t) - kudo's to Sembazuru
 // 0.1.05 - 2013-10-18 fixed bug in sort; removes default constructor; dynamic memory
-// 0.1.06 - 2013-10-19 faster sort? more dyn test.
+// 0.1.06 - 2013-10-19 faster sort, dynamic arrays, replaced sorted float array with indirection array
 //
 // Released to the public domain
 //
@@ -21,10 +21,10 @@
 RunningMedian::RunningMedian(uint8_t size)
 {
  _size = constrain(size, MEDIAN_MIN_SIZE, MEDIAN_MAX_SIZE);
- 
+
 #ifdef RUNNING_MEDIAN_USE_MALLOC
  _ar = (float *) malloc(_size * sizeof(float));
- _p = (uint8_t *) malloc(size * sizeof(uint8_t));
+ _p = (uint8_t *) malloc(_size * sizeof(uint8_t));
 #endif
 
  clear();
@@ -45,15 +45,16 @@ void RunningMedian::clear()
  _idx = 0;
  _sorted = false;
 
- // for (uint8_t i=0; i< _size; i++) _p[i] = i;
+ for (uint8_t i=0; i< _size; i++) _p[i] = i;
 }
 
 // adds a new value to the data-set
 // or overwrites the oldest if full.
 void RunningMedian::add(float value)
 {
- _ar[_idx++] = value;
+ _idx++;
  if (_idx >= _size) _idx = 0; // wrap around
+ _ar[_idx] = value;
  if (_cnt < _size) _cnt++;
  _sorted = false;
 }
@@ -64,7 +65,6 @@ float RunningMedian::getMedian()
  {
  if (_sorted == false) sort();
  return _ar[_p[_cnt/2]];
- // return _as[_cnt/2];
  }
  return NAN;
 }
@@ -74,9 +74,8 @@ float RunningMedian::getHighest()
 {
  if (_cnt > 0)
  {
- if (_sorted == false) sort();
+ if (_sorted == false) sort(); // assumes other fields are also retrieved otherwise inefficient
  return _ar[_p[_cnt-1]];
- // return _as[_cnt-1];
  }
  return NAN;
 }
@@ -87,7 +86,6 @@ float RunningMedian::getLowest()
  {
  if (_sorted == false) sort();
  return _ar[_p[0]];
- // return _as[0];
  }
  return NAN;
 }
@@ -110,9 +108,11 @@ float RunningMedian::getAverage(uint8_t nMedians)
  if (_cnt < nMedians) nMedians = _cnt; // when filling the array for first time
  uint8_t start = ((_cnt - nMedians)/2);
  uint8_t stop = start + nMedians;
+
  if (_sorted == false) sort();
+
  float sum = 0;
- for (uint8_t i = start; i < stop; i++) sum += _ar[_p[i]]; // _as[i];
+ for (uint8_t i = start; i < stop; i++) sum += _ar[_p[i]];
  return sum / nMedians;
  }
  return NAN;
@@ -125,15 +125,7 @@ uint8_t RunningMedian::getCount() { return _cnt; };
 
 void RunningMedian::sort()
 {
- // Serial.print("befor:\t");
- // for (uint8_t i=0; i< _cnt; i++) 
- // {
- // Serial.print(_ar[_p[i]]);
- // Serial.print('\t');
- // }
- // Serial.println();
-
- // sort all
+ // bubble sort with flag
  for (uint8_t i=0; i< _cnt-1; i++)
  {
  bool flag = true;
@@ -149,53 +141,8 @@ void RunningMedian::sort()
  }
  if (flag) break;
  }
- 
- // for (uint8_t i=0; i< _cnt-1; i++)
- // {
- // uint8_t m = i;
- // for (uint8_t j=i+1; j< _cnt; j++)
- // {
- // if (_ar[_p[j]] < _ar[_p[m]]) m = j;
- // }
- // if ( m != i )
- // {
- // uint8_t t = _p[i];
- // _p[i] = _p[m];
- // _p[m] = t;
- // }
- // }
- 
- // Serial.print("after:\t");
- // for (uint8_t i=0; i< _cnt; i++) 
- // {
- // Serial.print(_ar[_p[i]]);
- // Serial.print('\t');
- // }
- // Serial.println();
+
  _sorted = true;
 }
 
-// void RunningMedian::sort()
-// {
- // // copy
- // for (uint8_t i=0; i< _cnt; i++) _as[i] = _ar[i];
-
- // // sort all
- // for (uint8_t i=0; i< _cnt-1; i++)
- // {
- // uint8_t m = i;
- // for (uint8_t j=i+1; j< _cnt; j++)
- // {
- // if (_as[j] < _as[m]) m = j;
- // }
- // if (m != i)
- // {
- // float t = _as[m];
- // _as[m] = _as[i];
- // _as[i] = t;
- // }
- // }
- // _sorted = true;
-// }
-
 // END OF FILE

libraries/RunningMedian/RunningMedian.h

@@ -32,8 +32,9 @@
 
 // should at least be 5 to be practical
 // odd size results in a 'real' middle element.
+// even size takes the lower of the two middle elements (TODO)
 #define MEDIAN_MIN_SIZE 1
-#define MEDIAN_MAX_SIZE 19 // can be adjusted if needed
+#define MEDIAN_MAX_SIZE 19 // adjust if needed
 
 
 class RunningMedian
@@ -64,11 +65,9 @@ class RunningMedian
 
 #ifdef RUNNING_MEDIAN_USE_MALLOC
  float * _ar;
- // float * _as;
  uint8_t * _p;
 #else
  float _ar[MEDIAN_MAX_SIZE];
- // float _as[MEDIAN_MAX_SIZE];
  uint8_t _p[MEDIAN_MAX_SIZE];
 #endif
  void sort();

libraries/RunningMedian/examples/RunningMedian2/RunningMedian2.ino

@@ -11,7 +11,7 @@
 
 #include "RunningMedian.h"
 
-RunningMedian samples = RunningMedian(15);
+RunningMedian samples = RunningMedian(7);
 
 long count = 0;
 
@@ -29,16 +29,17 @@ void loop()
 
 void test1()
 {
- if (count % 20 == 0) Serial.println(F("\nmsec \tAnR \tSize \tCnt \tLow \tAvg \tAvg(3) \tMed \tHigh"));
+ if (count % 20 == 0) Serial.println(F("\nmsec \tAnR \tSize \tCnt \tLow \tAvg \tAvg(7) \tAvg(3) \tMed \tHigh"));
  count++;
- 
+
  long x = analogRead(A0);
 
  samples.add(x);
 
  float l = samples.getLowest();
  float m = samples.getMedian();
  float a = samples.getAverage();
+ float a7 = samples.getAverage(7);
  float a3 = samples.getAverage(3);
  float h = samples.getHighest();
  int s = samples.getSize();
@@ -56,6 +57,8 @@ void test1()
  Serial.print('\t');
  Serial.print(a, 2);
  Serial.print('\t');
+ Serial.print(a7, 2);
+ Serial.print('\t');
  Serial.print(a3, 2);
  Serial.print('\t');
  Serial.print(m);
@@ -64,3 +67,4 @@ void test1()
  delay(100);
 }
 
+