+ fix issue #33 - revert double to float as some uproc support float in HW

+ added const where possible
+ updated average demo + test-3.4

libraries/Statistic/README.txt

@@ -1,11 +0,0 @@
-
-2012-05-19
--------------
-This is a simple statistic library for the Arduino, version: 0.3.1
-previous versions are not available.
-
-2013-08-17 
-------------
-version: 0.3.2
-http://arduino.cc/playground/Main/Statistics
-

libraries/Statistic/Statistic.cpp

@@ -2,7 +2,7 @@
 //    FILE: Statistic.cpp
 //  AUTHOR: Rob dot Tillaart at gmail dot com
 //          modified at 0.3 by Gil Ross at physics dot org
-// VERSION: 0.3.3
+// VERSION: 0.3.4
 // PURPOSE: Recursive statistical library for Arduino
 //
 // NOTE: 2011-01-07 Gill Ross
@@ -44,6 +44,10 @@
 // 0.3.3 - 2015-03-07
 //   float -> double to support ARM (compiles)
 //   moved count() sum() min() max() to .h; for optimizing compiler
+// 0.3.4 - 2017-07-31
+//   Refactored const in many places
+//   [reverted] double to float on request as float is 99.99% of the cases
+//   good enough and float(32 bit) is supported in HW for some processors.
 //
 // Released to the public domain
 //
@@ -59,9 +63,9 @@ Statistic::Statistic()
 void Statistic::clear()
 {
     _cnt = 0;
-    _sum = 0.0;
+    _sum = 0;
-    _min = 0.0;
+    _min = 0;
-    _max = 0.0;
+    _max = 0;
 #ifdef STAT_USE_STDEV
     _ssqdif = 0.0;  // not _ssq but sum of square differences
     // which is SUM(from i = 1 to N) of
@@ -70,7 +74,7 @@ void Statistic::clear()
 }
 
 // adds a new value to the data-set
-void Statistic::add(double value)
+void Statistic::add(const float value)
 {
     if (_cnt == 0)
     {
@@ -86,14 +90,17 @@ void Statistic::add(double value)
 #ifdef STAT_USE_STDEV
     if (_cnt > 1)
     {
-        _store = (_sum / _cnt - value);
+        float _store = (_sum / _cnt - value);
         _ssqdif = _ssqdif + _cnt * _store * _store / (_cnt-1);
+        // ~10% faster but limits the amount of samples to 65K as _cnt*_cnt overflows
+        // float _store = _sum - _cnt * value;
+        // _ssqdif = _ssqdif + _store * _store / (_cnt*_cnt - _cnt);
     }
 #endif
 }
 
 // returns the average of the data-set added sofar
-double Statistic::average()
+float Statistic::average() const
 {
     if (_cnt == 0) return NAN; // original code returned 0
     return _sum / _cnt;
@@ -103,19 +110,19 @@ double Statistic::average()
 // http://www.suite101.com/content/how-is-standard-deviation-used-a99084
 #ifdef STAT_USE_STDEV
 
-double Statistic::variance()
+float Statistic::variance() const
 {
     if (_cnt == 0) return NAN; // otherwise DIV0 error
     return _ssqdif / _cnt;
 }
 
-double Statistic::pop_stdev()
+float Statistic::pop_stdev() const
 {
     if (_cnt == 0) return NAN; // otherwise DIV0 error
     return sqrt( _ssqdif / _cnt);
 }
 
-double Statistic::unbiased_stdev()
+float Statistic::unbiased_stdev() const
 {
     if (_cnt < 2) return NAN; // otherwise DIV0 error
     return sqrt( _ssqdif / (_cnt - 1));

libraries/Statistic/Statistic.h

@@ -4,7 +4,7 @@
 //    FILE: Statistic.h
 //  AUTHOR: Rob dot Tillaart at gmail dot com
 //          modified at 0.3 by Gil Ross at physics dot org
-// VERSION: 0.3.3
+// VERSION: 0.3.4
 // PURPOSE: Recursive Statistical library for Arduino
 // HISTORY: See Statistic.cpp
 //
@@ -12,41 +12,40 @@
 //
 
 // the standard deviation increases the lib (<100 bytes)
-// it can be in/excluded by un/commenting next line
+// it can be in/excluded by un/commenting next line  (compile time)
-#define STAT_USE_STDEV
+#define STAT_USE_STDEV 1
 
 #include <math.h>
 
-#define STATISTIC_LIB_VERSION "0.3.3"
+#define STATISTIC_LIB_VERSION "0.3.4"
 
 class Statistic
 {
 public:
-    Statistic();
+    Statistic();             // "switches on/off" stdev run time
-    void clear();
+    void clear();            // "switches on/off" stdev run time
-    void add(double);
+    void add(const float);
 
     // returns the number of values added
-    unsigned long count()   { return _cnt; }; // zero if empty
+    uint32_t count() const { return _cnt; }; // zero if empty
-    double sum()            { return _sum; }; // zero if empty
+    float sum() const      { return _sum; }; // zero if empty
-    double minimum()        { return _min; }; // zero if empty
+    float minimum() const  { return _min; }; // zero if empty
-    double maximum()        { return _max; }; // zero if empty
+    float maximum() const  { return _max; }; // zero if empty
-    double average();
+    float average() const;                   // NAN if empty
 
 #ifdef STAT_USE_STDEV
-    double variance();
+    float variance() const;                  // NAN if empty
-    double pop_stdev();	    // population stdev
+    float pop_stdev() const; // population stdev  // NAN if empty
-    double unbiased_stdev();
+    float unbiased_stdev() const;            // NAN if empty
 #endif
 
 protected:
-    unsigned long _cnt;
+    uint32_t _cnt;
-    double _store;           // store to minimise computation
+    float    _sum;
-    double _sum;
+    float    _min;
-    double _min;
+    float    _max;
-    double _max;
 #ifdef STAT_USE_STDEV
-    double _ssqdif;		    // sum of squares difference
+    float    _ssqdif;		    // sum of squares difference
 #endif
 };
 

libraries/Statistic/examples/Average/Average.ino

@@ -1,7 +1,7 @@
 //
 //    FILE: Average.ino
 //  AUTHOR: Rob dot Tillaart at gmail dot com
-// VERSION: 0.2
+// VERSION: 0.3
 // PURPOSE: Sample sketch for statistic library Arduino
 //
 
@@ -9,37 +9,48 @@
 
 Statistic myStats;
 
+uint32_t start;
+uint32_t stop;
+
 void setup(void)
 {
-  Serial.begin(9600);
+  Serial.begin(115200);
+  Serial.println(__FILE__);
   Serial.print("Demo Statistics lib ");
-  Serial.print(STATISTIC_LIB_VERSION);
+  Serial.println(STATISTIC_LIB_VERSION);
   myStats.clear(); //explicitly start clean
+  start = millis();
 }
 
 void loop(void)
 {
   long rn = random(0, 9999);
-  myStats.add(rn/100.0 + 1);
+  myStats.add(rn / 100.0 + 1);
   if (myStats.count() == 10000)
   {
-    Serial.print("  Count: ");
+    stop = millis();
+    Serial.print("        Count: ");
     Serial.println(myStats.count());
-    Serial.print("  Min: ");
+    Serial.print("          Min: ");
-    Serial.println(myStats.minimum(),4);
+    Serial.println(myStats.minimum(), 4);
-    Serial.print("  Max: ");
+    Serial.print("          Max: ");
-    Serial.println(myStats.maximum(),4);
+    Serial.println(myStats.maximum(), 4);
-    Serial.print("  Average: ");
+    Serial.print("      Average: ");
     Serial.println(myStats.average(), 4);
     // uncomment in Statistic.h file to use stdev
-    #ifdef STAT_USE_STDEV
+#ifdef STAT_USE_STDEV
+    Serial.print("     variance: ");
+    Serial.println(myStats.variance(), 4);
     Serial.print("    pop stdev: ");
     Serial.println(myStats.pop_stdev(), 4);
-    Serial.print("  unbias stdev: ");
+    Serial.print(" unbias stdev: ");
     Serial.println(myStats.unbiased_stdev(), 4);
-    #endif
+#endif
+    Serial.print("     time(ms): ");
+    Serial.println(stop - start);
     Serial.println("=====================================");
     myStats.clear();
     delay(1000);
+    start = millis();
   }
 }

libraries/Statistic/examples/Average/performance.0.3.4.txt

@@ -0,0 +1,236 @@
+C:\Users\Rob\Desktop\WORK\Arduino\libraries\Statistic\examples\Average\Average.ino
+Demo Statistics lib 0.3.4
+        Count: 10000
+          Min: 1.0100
+          Max: 100.9600
+      Average: 50.9408
+     variance: 835.0057
+    pop stdev: 28.8965
+ unbias stdev: 28.8979
+     time(ms): 2547
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9800
+      Average: 51.4161
+     variance: 839.9565
+    pop stdev: 28.9820
+ unbias stdev: 28.9835
+     time(ms): 2548
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9800
+      Average: 50.9561
+     variance: 833.2212
+    pop stdev: 28.8656
+ unbias stdev: 28.8670
+     time(ms): 2547
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9700
+      Average: 51.4648
+     variance: 849.5839
+    pop stdev: 29.1476
+ unbias stdev: 29.1491
+     time(ms): 2549
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9800
+      Average: 50.8610
+     variance: 842.0071
+    pop stdev: 29.0174
+ unbias stdev: 29.0188
+     time(ms): 2548
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9800
+      Average: 51.2327
+     variance: 816.5170
+    pop stdev: 28.5748
+ unbias stdev: 28.5762
+     time(ms): 2548
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9800
+      Average: 50.8115
+     variance: 835.1608
+    pop stdev: 28.8991
+ unbias stdev: 28.9006
+     time(ms): 2547
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9800
+      Average: 50.7948
+     variance: 842.5279
+    pop stdev: 29.0263
+ unbias stdev: 29.0278
+     time(ms): 2548
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9500
+      Average: 51.0943
+     variance: 831.8248
+    pop stdev: 28.8414
+ unbias stdev: 28.8428
+     time(ms): 2547
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9700
+      Average: 50.8915
+     variance: 836.6669
+    pop stdev: 28.9252
+ unbias stdev: 28.9266
+     time(ms): 2546
+=====================================
+        Count: 10000
+          Min: 1.0100
+          Max: 100.9800
+      Average: 50.8437
+     variance: 825.5516
+    pop stdev: 28.7324
+ unbias stdev: 28.7339
+     time(ms): 2548
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9800
+      Average: 51.3439
+     variance: 841.3205
+    pop stdev: 29.0055
+ unbias stdev: 29.0070
+     time(ms): 2547
+=====================================
+        Count: 10000
+          Min: 1.0400
+          Max: 100.9800
+      Average: 50.9124
+     variance: 833.6501
+    pop stdev: 28.8730
+ unbias stdev: 28.8744
+     time(ms): 2548
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9500
+      Average: 50.7144
+     variance: 825.8471
+    pop stdev: 28.7376
+ unbias stdev: 28.7390
+     time(ms): 2545
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9800
+      Average: 50.8693
+     variance: 832.8941
+    pop stdev: 28.8599
+ unbias stdev: 28.8613
+     time(ms): 2547
+=====================================
+        Count: 10000
+          Min: 1.0100
+          Max: 100.9800
+      Average: 50.4681
+     variance: 816.6417
+    pop stdev: 28.5769
+ unbias stdev: 28.5784
+     time(ms): 2546
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9700
+      Average: 50.8079
+     variance: 830.4100
+    pop stdev: 28.8168
+ unbias stdev: 28.8183
+     time(ms): 2548
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9800
+      Average: 50.9519
+     variance: 834.7280
+    pop stdev: 28.8917
+ unbias stdev: 28.8931
+     time(ms): 2548
+=====================================
+        Count: 10000
+          Min: 1.0100
+          Max: 100.9500
+      Average: 51.1545
+     variance: 842.0332
+    pop stdev: 29.0178
+ unbias stdev: 29.0193
+     time(ms): 2547
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9800
+      Average: 51.2756
+     variance: 838.0289
+    pop stdev: 28.9487
+ unbias stdev: 28.9502
+     time(ms): 2548
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9600
+      Average: 51.0082
+     variance: 836.6192
+    pop stdev: 28.9244
+ unbias stdev: 28.9258
+     time(ms): 2547
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9500
+      Average: 51.4703
+     variance: 828.6469
+    pop stdev: 28.7862
+ unbias stdev: 28.7877
+     time(ms): 2548
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9500
+      Average: 51.4059
+     variance: 822.9982
+    pop stdev: 28.6879
+ unbias stdev: 28.6894
+     time(ms): 2547
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9800
+      Average: 50.9745
+     variance: 832.5690
+    pop stdev: 28.8543
+ unbias stdev: 28.8557
+     time(ms): 2547
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9800
+      Average: 50.8281
+     variance: 836.5443
+    pop stdev: 28.9231
+ unbias stdev: 28.9245
+     time(ms): 2547
+=====================================
+        Count: 10000
+          Min: 1.0000
+          Max: 100.9800
+      Average: 51.0404
+     variance: 825.2975
+    pop stdev: 28.7280
+ unbias stdev: 28.7294
+     time(ms): 2548
+=====================================

libraries/Statistic/library.properties

@@ -1,5 +1,5 @@
 name=Statistics
-version=0.3.3
+version=0.3.4
 author=Rob Tillaart <rob.tillaart@gmail.com>
 maintainer=Rob Tillaart <rob.tillaart@gmail.com>
 sentence=Library with basic statistical functions for Arduino.