Arduino ci (#3)

* add Arduino-ci
* add unit test

.arduino-ci.yml

@@ -0,0 +1,7 @@
+compile:
+  # Choosing to run compilation tests on 2 different Arduino platforms
+  platforms:
+    - uno
+    - leonardo
+    - due
+    - zero

.github/workflows/arduino_test_runner.yml

@@ -0,0 +1,13 @@
+---
+name: Arduino CI
+
+on: [push, pull_request]
+
+jobs:
+  arduino_ci:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: Arduino-CI/action@master
+          #   Arduino-CI/action@v0.1.1

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2010-2020 Rob Tillaart
+Copyright (c) 2010-2021 Rob Tillaart
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -1,44 +1,55 @@
+
+[![Arduino CI](https://github.com/RobTillaart/Statistic/workflows/Arduino%20CI/badge.svg)](https://github.com/marketplace/actions/arduino_ci)
+[![License: MIT](https://img.shields.io/badge/license-MIT-green.svg)](https://github.com/RobTillaart/Statistic/blob/master/LICENSE)
+[![GitHub release](https://img.shields.io/github/release/RobTillaart/Statistic.svg?maxAge=3600)](https://github.com/RobTillaart/Statistic/releases)
+
+
 # Statistic
 
 Statistic library for Arduino includes sum, average, variance and std deviation
 
-# Description
+
+## Description
 
 The statistic library is made to get basic statistical information from a 
 one dimensional set of data, e.g. a stream of values of a sensor.
 
 The stability of the formulas is improved by the help of Gil Ross (Thanks!)
 
-The functions implemented are:
+## Interface
 
-* **clear(useStdDev)**
+- **Statistic(bool useStdDev = true)** Constructor, default use the standard deviation
-* **add(value)**
+functions. Setting this flag to **false** reduces math so slight increase of performance.
-* **count()**   returns zero if count == zero (of course)
+- **void clear(bool useStdDev = true)** resets all variables.
-* **sum()**     returns zero if count == zero
+- **void add(float value)**
-* **minimum()** returns zero if count == zero
+- **uint32_t count()** returns zero if count == zero (of course)
-* **maximum()** returns zero if count == zero
+- **float sum()**      returns zero if count == zero
-* **average()** returns NAN if count == zero
+- **float minimum()**  returns zero if count == zero
+- **float maximum()**  returns zero if count == zero
+- **float average()**  returns NAN if count == zero
 
-These three functions only work id useStdDev == true:
+These three functions only work if **useStdDev == true**
 
-* **variance()**         returns NAN if count == zero
+- **variance()**         returns NAN if count == zero
-* **pop_stdev()**        population stdev, returns NAN if count == zero
+- **pop_stdev()**        population stdev, returns NAN if count == zero
-* **unbiased_stdev()**   returnsNAN if count == zero
+- **unbiased_stdev()**   returnsNAN if count == zero
 
 
-# Operational
+## Operational
 
 See examples
 
-# FAQ
+## FAQ
+
+#### Q: Are individual samples still available?
 
-### Q: Are individual samples still available?
 The values added to the library are not stored in the lib as it would use lots 
 of memory quite fast. Instead a few calculated values are kept to be able to 
 calculate the most important statistics. 
 
 
-### Q: How many samples can the lib hold?  (internal variables and overflow)
+#### Q: How many samples can the lib hold?  (internal variables and overflow)
+
 The counter of samples is an **uint32_t**, implying a maximum of about **4 billion** samples. 
 In practice 'strange' things might happen before this number is reached. 
 There are two internal variables, **_sum** which is the sum of the values and **_ssq** 
@@ -52,10 +63,11 @@ This workaround has no influence on the standard deviation.
 
 !! Do not forget to add the expected average to the calculated average.
 
-*(Q: should this subtraction trick be build into the lib?)*
+- Q: should this subtraction trick be build into the lib?
 
 
-### Q: How about the precision of the library?
+#### Q: How about the precision of the library?
+
 The precision of the internal variables is restricted due to the fact 
 that they are 32 bit float (IEEE754). If the internal variable **_sum** has 
 a large value, adding relative small values to the dataset wouldn't 
@@ -69,11 +81,13 @@ but it works only if the samples are available and the they may be added
 in the sorted increasing order.
 
 
-### Q: When will internal var's overflow? esp. squared sum
+#### Q: When will internal var's overflow? esp. squared sum
+
 IEEE754 floats have a max value of about **+-3.4028235E+38**
 
 
-### Q: Why are there two functions for stdev?
+#### Q: Why are there two functions for stdev?
+
 There are two stdev functions the population stdev and the unbiased stdev. 
 See Wikipedia for an elaborate description of the difference between these two.
 

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: 0.4.1
+// VERSION: 0.4.2
 // PURPOSE: Recursive statistical library for Arduino
 //
 // NOTE: 2011-01-07 Gill Ross
@@ -53,15 +53,18 @@
 //          refactor
 //          Added flag to switch on the use of stdDev runtime. [idea marc.recksiedl]
 //  0.4.1   2020-06-19  fix library.json
-//
+//  0.4.2   2021-01-08  add Arduino-CI + unit tests
+
 
 #include "Statistic.h"
 
+
 Statistic::Statistic(bool useStdDev)
 {
   clear(useStdDev);
 }
 
+
 void Statistic::clear(bool useStdDev)	// useStdDev default true.
 {
     _cnt = 0;
@@ -74,6 +77,7 @@ void Statistic::clear(bool useStdDev)	// useStdDev default true.
     // which is SUM(from i = 1 to N) of f(i)-_ave_N)**2
 }
 
+
 // adds a new value to the data-set
 void Statistic::add(const float value)
 {
@@ -102,6 +106,7 @@ void Statistic::add(const float value)
     }
 }
 
+
 // returns the average of the data-set added sofar
 float Statistic::average() const
 {
@@ -109,6 +114,7 @@ float Statistic::average() const
     return _sum / _cnt;
 }
 
+
 // Population standard deviation = s = sqrt [ S ( Xi - µ )2 / N ]
 // http://www.suite101.com/content/how-is-standard-deviation-used-a99084
 float Statistic::variance() const
@@ -118,6 +124,7 @@ float Statistic::variance() const
     return _ssqdif / _cnt;
 }
 
+
 float Statistic::pop_stdev() const
 {
     if (!_useStdDev) return NAN;
@@ -125,6 +132,7 @@ float Statistic::pop_stdev() const
     return sqrt( _ssqdif / _cnt);
 }
 
+
 float Statistic::unbiased_stdev() const
 {
     if (!_useStdDev) return NAN;

Statistic.h

@@ -3,15 +3,17 @@
 //    FILE: Statistic.h
 //  AUTHOR: Rob dot Tillaart at gmail dot com
 //          modified at 0.3 by Gil Ross at physics dot org
-// VERSION: 0.4.1
+// VERSION: 0.4.2
 // PURPOSE: Recursive Statistical library for Arduino
 // HISTORY: See Statistic.cpp
 //
 
+
 #include <Arduino.h>
 #include <math.h>
 
-#define STATISTIC_LIB_VERSION "0.4.1"
+
+#define STATISTIC_LIB_VERSION       (F("0.4.2"))
 
 class Statistic
 {

library.json

@@ -18,7 +18,7 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/Statistic.git"
   },
-  "version":"0.4.1",
+  "version":"0.4.2",
   "frameworks": "arduino",
   "platforms": "*"
 }

library.properties

@@ -1,5 +1,5 @@
 name=Statistic
-version=0.4.1
+version=0.4.2
 author=Rob Tillaart <rob.tillaart@gmail.com>
 maintainer=Rob Tillaart <rob.tillaart@gmail.com>
 sentence=Library with basic statistical functions for Arduino. 

test/unit_test_001.cpp

@@ -0,0 +1,91 @@
+//
+//    FILE: unit_test_001.cpp
+//  AUTHOR: Rob Tillaart
+//    DATE: 2021-01-08
+// PURPOSE: unit tests for the Statistic library
+//          https://github.com/RobTillaart/Statistic
+//          https://github.com/Arduino-CI/arduino_ci/blob/master/REFERENCE.md
+//
+
+// supported assertions
+// ----------------------------
+// assertEqual(expected, actual);               // a == b
+// assertNotEqual(unwanted, actual);            // a != b
+// assertComparativeEquivalent(expected, actual);    // abs(a - b) == 0 or (!(a > b) && !(a < b))
+// assertComparativeNotEquivalent(unwanted, actual); // abs(a - b) > 0  or ((a > b) || (a < b))
+// assertLess(upperBound, actual);              // a < b
+// assertMore(lowerBound, actual);              // a > b
+// assertLessOrEqual(upperBound, actual);       // a <= b
+// assertMoreOrEqual(lowerBound, actual);       // a >= b
+// assertTrue(actual);
+// assertFalse(actual);
+// assertNull(actual);
+
+// // special cases for floats
+// assertEqualFloat(expected, actual, epsilon);    // fabs(a - b) <= epsilon
+// assertNotEqualFloat(unwanted, actual, epsilon); // fabs(a - b) >= epsilon
+// assertInfinity(actual);                         // isinf(a)
+// assertNotInfinity(actual);                      // !isinf(a)
+// assertNAN(arg);                                 // isnan(a)
+// assertNotNAN(arg);                              // !isnan(a)
+
+#include <ArduinoUnitTests.h>
+
+
+#include "Arduino.h"
+#include "Statistic.h"
+
+
+unittest_setup()
+{
+}
+
+unittest_teardown()
+{
+}
+
+
+unittest(test_constructor)
+{
+  fprintf(stderr, "VERSION: %s\n", STATISTIC_LIB_VERSION);
+
+  Statistic myStats;
+  assertEqual(0, myStats.count());
+}
+
+
+
+unittest(test_basic)
+{
+  fprintf(stderr, "VERSION: %s\n", STATISTIC_LIB_VERSION);
+
+  Statistic myStats;
+
+  for (int i = 1; i < 100; i++) myStats.add(i);
+  assertEqual(99, myStats.count());
+  assertEqualFloat(4950,    myStats.sum(),       0.0001);
+  assertEqualFloat(1,       myStats.minimum(),   0.0001);
+  assertEqualFloat(50,      myStats.average(),   0.0001);
+  assertEqualFloat(99,      myStats.maximum(),   0.0001);
+  assertEqualFloat(816.667, myStats.variance(),  0.001);     // note 1 digit less
+  assertEqualFloat(28.5774, myStats.pop_stdev(), 0.0001);
+  assertEqualFloat(28.7228, myStats.unbiased_stdev(), 0.0001);
+
+  myStats.clear();
+  assertEqualFloat(0,   myStats.sum(),       0.0001);
+  assertEqualFloat(0,   myStats.minimum(),   0.0001);
+  assertEqualFloat(0,   myStats.average(),   0.0001);
+  assertEqualFloat(0,   myStats.maximum(),   0.0001);
+  assertEqualFloat(0,   myStats.variance(),  0.0001);
+  assertEqualFloat(0,   myStats.pop_stdev(), 0.0001);
+  assertEqualFloat(0,   myStats.unbiased_stdev(), 0.0001);
+
+  assertEqual(0, myStats.count());
+
+}
+
+
+
+unittest_main()
+
+// --------