+ version 0.1.08

+ added getElement()
+ added getSortedElement()
+ added predict()
+ refactor getHighest(), getLowest()

libraries/RunningMedian/RunningMedian.cpp

@@ -1,7 +1,7 @@
 //
 //    FILE: RunningMedian.cpp
 //  AUTHOR: Rob dot Tillaart at gmail dot com
-// VERSION: 0.1.07
+// VERSION: 0.1.08
 // PURPOSE: RunningMedian library for Arduino
 //
 // HISTORY:
@@ -13,6 +13,7 @@
 // 0.1.05 - 2013-10-18 fixed bug in sort; removes default constructor; dynamic memory
 // 0.1.06 - 2013-10-19 faster sort, dynamic arrays, replaced sorted float array with indirection array
 // 0.1.07 - 2013-10-19 add correct median if _cnt is even.
+// 0.1.08 - 2013-10-20 add getElement(), add getSottedElement() add predict()
 //
 // Released to the public domain
 //
@@ -71,25 +72,9 @@ float RunningMedian::getMedian()
 }
 
 #ifdef RUNNING_MEDIAN_ALL
-float RunningMedian::getHighest()
-{
-    if (_cnt > 0)
-    {
-        if (_sorted == false) sort(); // assumes other fields are also retrieved otherwise inefficient
-        return _ar[_p[_cnt-1]];
-    }
-    return NAN;
-}
+float RunningMedian::getHighest() { return getSortedElement(_cnt-1); }
 
-float RunningMedian::getLowest()
-{
-    if (_cnt > 0)
-    {	
-        if (_sorted == false) sort();
-        return _ar[_p[0]];
-    }
-    return NAN;
-}
+float RunningMedian::getLowest() { return getSortedElement(0); }
 
 float RunningMedian::getAverage()
 {
@@ -119,6 +104,44 @@ float RunningMedian::getAverage(uint8_t nMedians)
     return NAN;
 }
 
+float RunningMedian::getElement(uint8_t n)
+{
+    if ((_cnt > 0) && (n < _cnt))
+    {
+        return _ar[n];
+    }
+    return NAN;
+}
+
+float RunningMedian::getSortedElement(uint8_t n)
+{
+    if ((_cnt > 0) && (n < _cnt))
+    {
+        if (_sorted == false) sort();
+        return _ar[_p[n]];
+    }
+    return NAN;
+}
+
+float RunningMedian::predict(uint8_t n)
+{
+    if ((_cnt > 0) && (n < _cnt/2))
+    {
+        float med = getMedian();  // takes care of sorting !
+        if (_cnt & 0x01)
+        {
+            return max(med - _ar[_p[_cnt/2-n]], _ar[_p[_cnt/2+n]] - med);
+        }
+        else
+        {
+            float f1 = (_ar[_p[_cnt/2 - n]] + _ar[_p[_cnt/2 - n - 1]])/2;
+            float f2 = (_ar[_p[_cnt/2 + n]] + _ar[_p[_cnt/2 + n - 1]])/2;
+            return max(med - f1, f2 - med)/2;
+        }
+    }
+    return NAN;
+}
+
 uint8_t RunningMedian::getSize() { return _size; };
 
 uint8_t RunningMedian::getCount() { return _cnt; };

libraries/RunningMedian/RunningMedian.h

@@ -4,7 +4,7 @@
 //    FILE: RunningMedian.h
 //  AUTHOR: Rob dot Tillaart at gmail dot com
 // PURPOSE: RunningMedian library for Arduino
-// VERSION: 0.1.07
+// VERSION: 0.1.08
 //     URL: http://arduino.cc/playground/Main/RunningMedian
 // HISTORY: See RunningMedian.cpp
 //
@@ -53,6 +53,10 @@ public:
     float getHighest();                 // returns highest element
     float getLowest();                  // return lowest element
 
+    float getElement(uint8_t n);        // get n'th element from the values in time order
+    float getSortedElement(uint8_t n);  // get n'th element from the values in size order
+    float predict(uint8_t n);           // predict the max change of median after n additions
+
     uint8_t getSize();                  // returns size of internal buffer
     uint8_t getCount();                 // returns current used elements, getCount() <= getSize()
 #endif

libraries/RunningMedian/examples/RunningMedian2/RunningMedian2.ino

@@ -11,7 +11,7 @@
 
 #include "RunningMedian.h"
 
-RunningMedian samples = RunningMedian(7);
+RunningMedian samples = RunningMedian(100);
 
 long count = 0;
 
@@ -29,7 +29,7 @@ void loop()
 
 void test1()
 {
-  if (count % 20 == 0) Serial.println(F("\nmsec \tAnR \tSize \tCnt \tLow \tAvg \tAvg(7) \tAvg(3) \tMed \tHigh"));
+  if (count % 20 == 0) Serial.println(F("\nmsec \tAnR \tSize \tCnt \tLow \tAvg \tAvg(7) \tAvg(3) \tMed \tHigh \tPre(1) \tPre(2)"));
   count++;
 
   long x = analogRead(A0);
@@ -44,6 +44,8 @@ void test1()
   float h = samples.getHighest();
   int s = samples.getSize();
   int c = samples.getCount();
+  float p1 = samples.predict(1);
+  float p2 = samples.predict(2);
 
   Serial.print(millis());
   Serial.print('\t');
@@ -63,7 +65,12 @@ void test1()
   Serial.print('\t');
   Serial.print(m);
   Serial.print('\t');
-  Serial.println(h);
+  Serial.print(h);
+  Serial.print('\t');
+  Serial.print(p1, 2);
+  Serial.print('\t');
+  Serial.println(p2, 2);
+
   delay(100);
 }
 

libraries/RunningMedian/keywords.txt

@@ -21,6 +21,9 @@ getHighest	KEYWORD2
 getLowest	KEYWORD2
 getSize	KEYWORD2
 getCount	KEYWORD2
+getElement	KEYWORD2
+getSortedElement	KEYWORD2
+predict KEYWORD2
 getStatus	KEYWORD2
 
 #######################################