+ version 0.3.3

+ changed float -> double to support ARM series + moved some code to .h file so compiler can optimize more + reindented

Author: RobTillaart

libraries/Statistic/Statistic.cpp

@@ -1,30 +1,30 @@
 //
 // FILE: Statistic.cpp
-// AUTHOR: Rob dot Tillaart at gmail dot com 
+// AUTHOR: Rob dot Tillaart at gmail dot com
 // modified at 0.3 by Gil Ross at physics dot org
-// VERSION: see STATISTIC_LIB_VERSION in .h
+// VERSION: 0.3.3
 // PURPOSE: Recursive statistical library for Arduino
 //
 // NOTE: 2011-01-07 Gill Ross
 // Rob Tillaart's Statistic library uses one-pass of the data (allowing
 // each value to be discarded), but expands the Sum of Squares Differences to
 // difference the Sum of Squares and the Average Squared. This is susceptible
-// to bit length precision errors with the float type (only 5 or 6 digits 
+// to bit length precision errors with the float type (only 5 or 6 digits
 // absolute precision) so for long runs and high ratios of
-// the average value to standard deviation the estimate of the 
+// the average value to standard deviation the estimate of the
 // standard error (deviation) becomes the difference of two large
 // numbers and will tend to zero.
 //
 // For small numbers of iterations and small Average/SE th original code is
 // likely to work fine.
-// It should also be recognised that for very large samples, questions 
+// It should also be recognised that for very large samples, questions
 // of stability of the sample assume greater importance than the
 // correctness of the asymptotic estimators.
 //
 // This recursive algorithm, which takes slightly more computation per
 // iteration is numerically stable.
 // It updates the number, mean, max, min and SumOfSquaresDiff each step to
-// deliver max min average, population standard error (standard deviation) and 
+// deliver max min average, population standard error (standard deviation) and
 // unbiassed SE.
 // -------------
 //
@@ -34,13 +34,16 @@
 // 0.2.01 - 2010-10-30
 // added minimim, maximum, unbiased stdev,
 // changed counter to long -> int overflows @32K samples
-// 0.3 - 2011-01-07 
+// 0.3 - 2011-01-07
 // branched from 0.2.01 version of Rob Tillaart's code
 // 0.3.1 - minor edits
 // 0.3.2 - 2012-11-10
-// minor edits 
+// minor edits
 // changed count -> unsigned long allows for 2^32 samples
 // added variance()
+// 0.3.3 - 2015-03-07
+// float -> double to support ARM (compiles)
+// moved count() sum() min() max() to .h; for optimizing compiler
 //
 // Released to the public domain
 //
@@ -49,98 +52,73 @@
 
 Statistic::Statistic()
 {
-clear();
+ clear();
 }
 
 // resets all counters
 void Statistic::clear()
-{ 
-_cnt = 0;
-_sum = 0.0;
-_min = 0.0;
-_max = 0.0;
+{
+ _cnt = 0;
+ _sum = 0.0;
+ _min = 0.0;
+ _max = 0.0;
 #ifdef STAT_USE_STDEV
-_ssqdif = 0.0; // not _ssq but sum of square differences
-  // which is SUM(from i = 1 to N) of 
-  // (f(i)-_ave_N)**2
+ _ssqdif = 0.0; // not _ssq but sum of square differences
+ // which is SUM(from i = 1 to N) of
+ // (f(i)-_ave_N)**2
 #endif
 }
 
 // adds a new value to the data-set
-void Statistic::add(float f)
+void Statistic::add(double value)
 {
-if (_cnt == 0)
-{
-_min = f;
-_max = f;
-} else {
-if (f < _min) _min = f;
-if (f > _max) _max = f; 
+ if (_cnt == 0)
+ {
+ _min = value;
+ _max = value;
+ } else {
+ if (value < _min) _min = value;
+ else if (value > _max) _max = value;
  }
-_sum += f;
-_cnt++;
-
-#ifdef STAT_USE_STDEV 
- if (_cnt >1) 
-{
- _store = (_sum / _cnt - f);
+ _sum += value;
+ _cnt++;
+ 
+#ifdef STAT_USE_STDEV
+ if (_cnt > 1)
+ {
+  _store = (_sum / _cnt - value);
  _ssqdif = _ssqdif + _cnt * _store * _store / (_cnt-1);
- } 
+ }
 #endif
 }
 
-// returns the number of values added
-unsigned long Statistic::count()
-{
-return _cnt;
-}
-
 // returns the average of the data-set added sofar
-float Statistic::average()
-{
-if (_cnt == 0) return NAN; // original code returned 0
-return _sum / _cnt;
-}
-
-// returns the sum of the data-set (0 if no values added)
-float Statistic::sum()
+double Statistic::average()
 {
-return _sum;
+ if (_cnt == 0) return NAN; // original code returned 0
+ return _sum / _cnt;
 }
 
-// returns the sum of the data-set (0 if no values added)
-float Statistic::minimum()
-{
-return _min;
-}
-
-// returns the sum of the data-set (0 if no values added)
-float Statistic::maximum()
-{
-return _max;
-}
-
-
 // Population standard deviation = s = sqrt [ S ( Xi - µ )2 / N ]
 // http://www.suite101.com/content/how-is-standard-deviation-used-a99084
-#ifdef STAT_USE_STDEV 
+#ifdef STAT_USE_STDEV
 
-float Statistic::variance()
+double Statistic::variance()
 {
-if (_cnt == 0) return NAN; // otherwise DIV0 error
-return _ssqdif / _cnt;
+ if (_cnt == 0) return NAN; // otherwise DIV0 error
+ return _ssqdif / _cnt;
 }
 
-float Statistic::pop_stdev()
+double Statistic::pop_stdev()
 {
-if (_cnt == 0) return NAN; // otherwise DIV0 error
-return sqrt( _ssqdif / _cnt);
+ if (_cnt == 0) return NAN; // otherwise DIV0 error
+ return sqrt( _ssqdif / _cnt);
 }
 
-float Statistic::unbiased_stdev()
+double Statistic::unbiased_stdev()
 {
-if (_cnt < 2) return NAN; // otherwise DIV0 error
-return sqrt( _ssqdif / (_cnt - 1));
+ if (_cnt < 2) return NAN; // otherwise DIV0 error
+ return sqrt( _ssqdif / (_cnt - 1));
 }
 
 #endif

libraries/Statistic/Statistic.h

@@ -1,9 +1,10 @@
 #ifndef Statistic_h
 #define Statistic_h
-// 
+//
 // FILE: Statistic.h
-// AUTHOR: Rob dot Tillaart at gmail dot com 
+// AUTHOR: Rob dot Tillaart at gmail dot com
 // modified at 0.3 by Gil Ross at physics dot org
+// VERSION: 0.3.3
 // PURPOSE: Recursive Statistical library for Arduino
 // HISTORY: See Statistic.cpp
 //
@@ -16,34 +17,36 @@
 
 #include <math.h>
 
-#define STATISTIC_LIB_VERSION "0.3.2"
+#define STATISTIC_LIB_VERSION "0.3.3"
 
-class Statistic 
+class Statistic
 {
-public:
-Statistic();
-void clear();
-void add(float);
-unsigned long count();
-float sum();
-float average();
-float minimum();
-float maximum();
+public:
+ Statistic();
+ void clear();
+ void add(double);
+
+ // returns the number of values added
+ unsigned long count() { return _cnt; }; // zero if empty
+ double sum() { return _sum; }; // zero if empty
+ double minimum() { return _min; }; // zero if empty
+ double maximum() { return _max; }; // zero if empty
+ double average();
 
 #ifdef STAT_USE_STDEV
-float variance();
-float pop_stdev(); // population stdev
-float unbiased_stdev();
+ double variance();
+ double pop_stdev(); // population stdev
+ double unbiased_stdev();
 #endif
 
 protected:
-unsigned long _cnt;
-float _store; // store to minimise computation
-float _sum;
-float _min;
-float _max;
+ unsigned long _cnt;
+ double _store; // store to minimise computation
+ double _sum;
+ double _min;
+ double _max;
 #ifdef STAT_USE_STDEV
-float _ssqdif; // sum of squares difference
+ double _ssqdif; // sum of squares difference
 #endif
 };