0.1.0 Student

2024-09-19 08:36:08 -04:00 · 2024-07-23 14:06:43 +02:00 · 2024-07-23 14:06:43 +02:00 · 710ef84c52
commit 710ef84c52
parent da2e9fe077
16 changed files with 831 additions and 0 deletions
--- a/libraries/Student/.arduino-ci.yml
+++ b/libraries/Student/.arduino-ci.yml
@ -0,0 +1,34 @@
+platforms:
+  rpipico:
+    board: rp2040:rp2040:rpipico
+    package: rp2040:rp2040
+    gcc:
+      features:
+      defines:
+        - ARDUINO_ARCH_RP2040
+      warnings:
+      flags:
+
+packages:
+  rp2040:rp2040:
+    url: https://github.com/earlephilhower/arduino-pico/releases/download/global/package_rp2040_index.json
+
+compile:
+  # Choosing to run compilation tests on 2 different Arduino platforms
+  platforms:
+    - uno
+    # - due
+    # - zero
+    # - leonardo
+    - m4
+    - esp32
+    - esp8266
+    # - mega2560
+    - rpipico
+  libraries:
+    - MultiMap
+
+unittest:
+  # These dependent libraries will be installed
+  libraries:
+    - MultiMap
--- a/libraries/Student/.github/FUNDING.yml
+++ b/libraries/Student/.github/FUNDING.yml
@ -0,0 +1,4 @@
+# These are supported funding model platforms
+
+github: RobTillaart
+custom: "https://www.paypal.me/robtillaart"
--- a/libraries/Student/.github/workflows/arduino-lint.yml
+++ b/libraries/Student/.github/workflows/arduino-lint.yml
@ -0,0 +1,13 @@
+name: Arduino-lint
+
+on: [push, pull_request]
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - uses: actions/checkout@v4
+      - uses: arduino/arduino-lint-action@v1
+        with:
+          library-manager: update
+          compliance: strict
--- a/libraries/Student/.github/workflows/arduino_test_runner.yml
+++ b/libraries/Student/.github/workflows/arduino_test_runner.yml
@ -0,0 +1,17 @@
+name: Arduino CI
+
+on: [push, pull_request]
+
+jobs:
+  runTest:
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 2.6
+      - run: |
+          gem install arduino_ci
+          arduino_ci.rb
--- a/libraries/Student/.github/workflows/jsoncheck.yml
+++ b/libraries/Student/.github/workflows/jsoncheck.yml
@ -0,0 +1,18 @@
+name: JSON check
+
+on:
+  push:
+    paths:
+      - '**.json'
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - uses: actions/checkout@v4
+      - name: json-syntax-check
+        uses: limitusus/json-syntax-check@v2
+        with:
+          pattern: "\\.json$"
--- a/libraries/Student/CHANGELOG.md
+++ b/libraries/Student/CHANGELOG.md
@ -0,0 +1,11 @@
+# Change Log Student
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](http://keepachangelog.com/)
+and this project adheres to [Semantic Versioning](http://semver.org/).
+
+
+## [0.1.0] - 2024-07-22
+- initial version
+
--- a/libraries/Student/LICENSE
+++ b/libraries/Student/LICENSE
@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2024-2024 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
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
--- a/libraries/Student/README.md
+++ b/libraries/Student/README.md
@ -0,0 +1,187 @@
+
+[![Arduino CI](https://github.com/RobTillaart/Student/workflows/Arduino%20CI/badge.svg)](https://github.com/marketplace/actions/arduino_ci)
+[![Arduino-lint](https://github.com/RobTillaart/Student/actions/workflows/arduino-lint.yml/badge.svg)](https://github.com/RobTillaart/Student/actions/workflows/arduino-lint.yml)
+[![JSON check](https://github.com/RobTillaart/Student/actions/workflows/jsoncheck.yml/badge.svg)](https://github.com/RobTillaart/Student/actions/workflows/jsoncheck.yml)
+[![GitHub issues](https://img.shields.io/github/issues/RobTillaart/Student.svg)](https://github.com/RobTillaart/Student/issues)
+
+[![License: MIT](https://img.shields.io/badge/license-MIT-green.svg)](https://github.com/RobTillaart/Student/blob/master/LICENSE)
+[![GitHub release](https://img.shields.io/github/release/RobTillaart/Student.svg?maxAge=3600)](https://github.com/RobTillaart/Student/releases)
+[![PlatformIO Registry](https://badges.registry.platformio.org/packages/robtillaart/library/Student.svg)](https://registry.platformio.org/libraries/robtillaart/Student)
+
+
+# Student
+
+Arduino library for Student or T-distribution math.
+
+
+## Description
+
+**Experimental**
+
+Student is an experimental Arduino library to estimate the mean (average) of a population
+based upon a (very) small sample (selection).
+Goal is to calculate the interval for which there is a certain confidence e.g. 95%, 
+that the population mean lies between the estimated mean from the sample +- some intervalDelta.
+
+The 0.1.x version of the library is limited to a maximum of 20 samples to keep RAM usage 
+relative low. 
+It uses a lookup table (LUT) for a sample size up to 20, and for five discrete confidence 
+levels 80%, 90%, 95%, 98% and 99% ==> size table = 20 x 5 = 100 floats. 
+The table encodes the 100 floats as uint16_t to save 50% of the RAM needed.
+
+The library allows to calculate the interval after every addition until the internal buffer
+of 20 samples is full. Note that at least 2 samples are needed to calculate the interval.
+
+
+### StudentTable.h
+
+The table is defined in the file **StudentTable.h** and generated from a spreadsheet.
+
+If one need to extend the sample size, the file contains commented values for sample size 21-100.
+One has to adjust **STUDENT_MAX_SIZE** in **StudentTable.h** too (max 255).
+Note this will cost extra RAM.
+
+If one wants to reduce the sample size / RAM, one can comment part of the table not needed.
+One has to adjust **STUDENT_MAX_SIZE** too.
+
+
+### Application example
+
+If one wants to estimate the average temperature, one can measure it constantly and
+calculate the average from all measurements. This may take up to 3600 samples per hour.
+With the Student library one can measure the temperature once every 5 minutes.
+This give 12 samples from which one can calculate the interval of the average temperature 
+with 95% confidence.
+
+This takes far less samples and calculation time and might meet the insights you need.
+Furthermore using this method can be ideal in an low power environment (e.g. remote, 
+battery powered sensor, with long sleep) to get the information you need.
+
+
+### History
+
+The T-distribution is developed by William Gosset, head experimental brewer, in 1908 while 
+working for Guinness Beer. His goal was to guard a constant quality of the beer brewed.
+He needed a method to determine the quality of the raw materials like grains, malt and hops,
+based on small samples from the fields. 
+For this he invented the t-distribution and published it under the name Student. 
+Therefore this distribution is also known as the Student distribution.
+
+
+### Accuracy / precision
+
+The version 0.1.x uses float for internal storage. This means precision is at most 6-7 digits.
+
+The version 0.1.x lookup table has 20 x 5 values with 3 decimals, coded as an uint16_t (for RAM)
+This allows about 3-4 digits precision for the found interval.
+
+The 0.1.x version does not interpolate the confidence level (yet), and only support 5 distinct levels.
+This interpolation (between 80-99) is planned to be implemented in the future.
+If a non supported confidence level is used, the library will use 95%.
+
+If you need only one confidence interval you could strip the lookup table to one column.
+
+
+### Character
+
+|  parameter  |  name  |  ALT-code  |  char |
+|:-----------:|:------:|:----------:|:-----:|
+|  mean       |  mu    |  ALT-230   |   µ   |
+|  stddev     | sigma  |  ALT-229   |   σ   |
+|  CDF        |  phi   |  ALT-232   |   Φ   |  ALT-237 for lower case
+|  plus minus |        |  ALT-0177  |   ±   |
+
+- https://altcodesguru.com/greek-alt-codes.html
+
+
+### Related
+
+- https://en.wikipedia.org/wiki/Normal_distribution
+- https://en.wikipedia.org/wiki/Student_distribution
+- https://sphweb.bumc.bu.edu/otlt/mph-modules/bs/bs704_probability/bs704_probability9.html
+- https://github.com/RobTillaart/Gauss
+- https://github.com/RobTillaart/Multimap
+- https://github.com/RobTillaart/Statistic  (more stat links there).
+- https://github.com/RobTillaart/Student
+
+
+## Interface
+
+```cpp
+#include Student.h
+```
+
+### Constructor + meta
+
+- **Student()** constructor. 0.1.x has a fixed max sample size STUDENT_MAX_SIZE = 20.
+- **uint8_t getSize()** returns STUDENT_MAX_SIZE == 20.
+- **uint8_t getCount()** returns the number of samples added.
+Returns value between 0 .. getSize().
+- **void reset()** resets internal counter to zero.
+
+### Add
+
+- **bool add(float value)** adds one sample.
+Returns false if internal buffer is full (count >= size).
+- **bool add(float \*array, uint8_t size)** adds an array of samples.
+Returns false if the internal buffer would "overflow".
+
+### Math
+
+- **float mean()** returns mean (average) of the samples added. 
+This is the estimated mean of the population from which the samples are taken.
+- **float variance()** returns variance of the samples added.
+- **float deviation()** returns standard deviation of the samples added.
+- **float estimatedDeviation()** returns estimated deviation of the 
+estimated mean (based upon the samples).
+
+### Interval
+
+Confidence should be 80, 90, 95, 98 or 99. 
+The confidence level is not interpolated and incorrect values are replaced by 95%.
+
+- **float intervalDelta(int confidence)** returns the delta to be added
+oor subtracted to the mean to determine the confidence interval.
+- **float meanLower(int confidence)** returns mean - intervalDelta.
+- **float meanUpper(int confidence)** returns mean + intervalDelta.
+
+
+## Future
+
+#### Must
+
+- documentation
+- improve upon function names.
+- test test test
+
+#### Should
+
+- t test example.
+- optimize code, e.g. cache values for performance.
+- optimize lookup table, PROGMEM for footprint?
+- dynamic allocation for sizes > 20
+  - or derived classes, student30, student40, student50, student100?
+  - linear interpolation for values > 10 (performance?)
+- add interpolation to **intervalDelta()** so confidence level (0.2.x)
+  could be any integer value from 80-99 (maybe even float?)
+
+#### Could
+
+- add examples
+- add unit tests
+- replace look up table with a formula? (performance drop!!)
+- access function for internal array to access samples?
+- template class instead of STUDENT_MAX_SIZE? (becomes different types).
+- circular buffer for the samples? Running T-test?
+
+#### Won't (unless requested)
+
+
+## Support
+
+If you appreciate my libraries, you can support the development and maintenance.
+Improve the quality of the libraries by providing issues and Pull Requests, or
+donate through PayPal or GitHub sponsors.
+
+Thank you,
+
--- a/libraries/Student/Student.cpp
+++ b/libraries/Student/Student.cpp
@ -0,0 +1,11 @@
+//
+//    FILE: Student.cpp
+//  AUTHOR: Rob Tillaart
+// VERSION: 0.1.0
+// PURPOSE: Arduino library for Student or T-distribution math.
+//    DATE: 2024-07-22
+
+//  placeholder
+
+//  -- END OF FILE --
+
--- a/libraries/Student/Student.h
+++ b/libraries/Student/Student.h
@ -0,0 +1,142 @@
+#pragma once
+//
+//    FILE: Student.h
+//  AUTHOR: Rob Tillaart
+// VERSION: 0.1.0
+// PURPOSE: Arduino library for Student or T-distribution math.
+//    DATE: 2024-07-22
+
+
+#include "Arduino.h"
+#include "StudentTable.h"
+
+#define STUDENT_LIB_VERSION       (F("0.1.0"))
+
+
+class Student
+{
+public:
+  Student()
+  {
+    _size = STUDENT_MAX_SIZE;
+    _count = 0;
+  }
+
+  uint8_t getSize()
+  {
+    return _size;
+  }
+
+  uint8_t getCount()
+  {
+    return _count;
+  }
+
+  void reset()
+  {
+    _count = 0;
+  }
+
+  //
+  //  ADD
+  //
+  bool add(float value)
+  {
+    if (_count >= _size) return false;
+    _value[_count++] = value;
+    return true;
+  }
+
+  bool add(float *array, uint8_t size)
+  {
+    if (_count + size > _size) return false;
+    for (int i = 0; i < size; i++)
+    {
+      add(array[i]);
+    }
+    return true;
+  }
+
+  //
+  //  MATH
+  //
+  float mean()
+  {
+    float sum = 0;
+    for (int i = 0; i < _count; i++)
+    {
+      sum += _value[i];
+    }
+    return sum / _count;
+  }
+
+  float variance()
+  {
+    if (_count < 2) return NAN;
+    float m = mean();
+    float var = 0;
+    for (int i = 0; i < _count; i++)
+    {
+      var += (_value[i] - m)*(_value[i] - m);
+    }
+    var /= (_count - 1);
+    return var;
+  }
+
+  float deviation()
+  {
+    if (_count < 2) return NAN;
+    float var = variance();
+    return sqrt(var);
+  }
+
+  float estimatedDeviation()
+  {
+    if (_count < 2) return NAN;
+    float dev = deviation();
+    return dev / sqrt(_count);
+  }
+
+  //
+  //  INTERVAL
+  //
+
+  float intervalDelta(int confidence)
+  {
+    if (_count < 2) return NAN;
+    //  degrees freedom
+    int df = _count - 1;
+    int idx = 2;  //  95% default
+    if (confidence == 80) idx = 0;
+    if (confidence == 90) idx = 1;
+    if (confidence == 98) idx = 3;
+    if (confidence == 99) idx = 4;
+
+    //  interpolation possible
+    float t = StudentLUT[df][idx] * 0.001;
+    return estimatedDeviation() * t;
+  }
+
+  float meanLower(int confidence)
+  {
+    return mean() - intervalDelta(confidence);
+  }
+
+  float meanUpper(int confidence)
+  {
+    return mean() + intervalDelta(confidence);
+  }
+
+
+private:
+
+  uint8_t _size;
+  uint8_t _count;
+  float   _mean = 0;
+  float   _value[STUDENT_MAX_SIZE];
+
+};
+
+
+//  -- END OF FILE --
+
--- a/libraries/Student/StudentTable.h
+++ b/libraries/Student/StudentTable.h
@ -0,0 +1,159 @@
+#pragma once
+//
+//    FILE: StudentTable.h
+//  AUTHOR: Rob Tillaart
+// VERSION: 0.1.0
+// PURPOSE: Arduino library for Student or T-distribution math.
+//    DATE: 2024-07-22
+
+//  lookup table, do not change (unless you know what you do).
+//
+//  spreadsheet = ROUND(1000 * T.INV.2T(C$4;$B7))
+//
+//  x = degrees of freedom
+//  y = confidence level 0.1, 0.05, 0.025, 0.01, 0.005 (single ended)
+//  values are multiplied by 1000, to save RAM.
+//
+
+
+//  command line overrule possible
+#ifndef STUDENT_MAX_SIZE
+#define STUDENT_MAX_SIZE          (20)
+#endif
+
+
+//  uses 200 bytes of RAM
+uint16_t StudentLUT[STUDENT_MAX_SIZE][5]
+{
+  // 80%   90%    95%    98%    99%
+  //---------------------------------
+  { 3078, 6314, 12706, 31821, 63657},  //  n = 1
+  { 1886, 2920,  4303,  6965,  9925},
+  { 1638, 2353,  3182,  4541,  5841},
+  { 1533, 2132,  2776,  3747,  4604},
+  { 1476, 2015,  2571,  3365,  4032},
+
+  { 1440, 1943,  2447,  3143,  3707},
+  { 1415, 1895,  2365,  2998,  3499},
+  { 1397, 1860,  2306,  2896,  3355},
+  { 1383, 1833,  2262,  2821,  3250},
+  { 1372, 1812,  2228,  2764,  3169},
+
+  { 1363, 1796,  2201,  2718,  3106},
+  { 1356, 1782,  2179,  2681,  3055},
+  { 1350, 1771,  2160,  2650,  3012},
+  { 1345, 1761,  2145,  2624,  2977},
+  { 1341, 1753,  2131,  2602,  2947},
+
+  { 1337, 1746,  2120,  2583,  2921},
+  { 1333, 1740,  2110,  2567,  2898},
+  { 1330, 1734,  2101,  2552,  2878},
+  { 1328, 1729,  2093,  2539,  2861},
+  { 1325, 1725,  2086,  2528,  2845}   //  n = 20
+};
+
+
+/*
+  { 1323, 1721, 2080, 2518, 2831},   //  n = 21
+  { 1321, 1717, 2074, 2508, 2819},
+  { 1319, 1714, 2069, 2500, 2807},
+  { 1318, 1711, 2064, 2492, 2797},
+  { 1316, 1708, 2060, 2485, 2787},
+
+  { 1315, 1706, 2056, 2479, 2779},
+  { 1314, 1703, 2052, 2473, 2771},
+  { 1313, 1701, 2048, 2467, 2763},
+  { 1311, 1699, 2045, 2462, 2756},
+  { 1310, 1697, 2042, 2457, 2750},   //  n = 30
+
+  { 1309, 1696, 2040, 2453, 2744},
+  { 1309, 1694, 2037, 2449, 2738},
+  { 1308, 1692, 2035, 2445, 2733},
+  { 1307, 1691, 2032, 2441, 2728},
+  { 1306, 1690, 2030, 2438, 2724},
+
+  { 1306, 1688, 2028, 2434, 2719},
+  { 1305, 1687, 2026, 2431, 2715},
+  { 1304, 1686, 2024, 2429, 2712},
+  { 1304, 1685, 2023, 2426, 2708},
+  { 1303, 1684, 2021, 2423, 2704},  //  n = 40
+
+  { 1303, 1683, 2020, 2421, 2701},
+  { 1302, 1682, 2018, 2418, 2698},
+  { 1302, 1681, 2017, 2416, 2695},
+  { 1301, 1680, 2015, 2414, 2692},
+  { 1301, 1679, 2014, 2412, 2690},
+
+  { 1300, 1679, 2013, 2410, 2687},
+  { 1300, 1678, 2012, 2408, 2685},
+  { 1299, 1677, 2011, 2407, 2682},
+  { 1299, 1677, 2010, 2405, 2680},
+  { 1299, 1676, 2009, 2403, 2678},  //  n = 50
+
+  { 1298, 1675, 2008, 2402, 2676},
+  { 1298, 1675, 2007, 2400, 2674},
+  { 1298, 1674, 2006, 2399, 2672},
+  { 1297, 1674, 2005, 2397, 2670},
+  { 1297, 1673, 2004, 2396, 2668},
+
+  { 1297, 1673, 2003, 2395, 2667},
+  { 1297, 1672, 2002, 2394, 2665},
+  { 1296, 1672, 2002, 2392, 2663},
+  { 1296, 1671, 2001, 2391, 2662},
+  { 1296, 1671, 2000, 2390, 2660},  //  n = 60
+
+  { 1296, 1670, 2000, 2389, 2659},
+  { 1295, 1670, 1999, 2388, 2657},
+  { 1295, 1669, 1998, 2387, 2656},
+  { 1295, 1669, 1998, 2386, 2655},
+  { 1295, 1669, 1997, 2385, 2654},
+
+  { 1295, 1668, 1997, 2384, 2652},
+  { 1294, 1668, 1996, 2383, 2651},
+  { 1294, 1668, 1995, 2382, 2650},
+  { 1294, 1667, 1995, 2382, 2649},
+  { 1294, 1667, 1994, 2381, 2648},  //  n = 70
+
+  { 1294, 1667, 1994, 2380, 2647},
+  { 1293, 1666, 1993, 2379, 2646},
+  { 1293, 1666, 1993, 2379, 2645},
+  { 1293, 1666, 1993, 2378, 2644},
+  { 1293, 1665, 1992, 2377, 2643},
+
+  { 1293, 1665, 1992, 2376, 2642},
+  { 1293, 1665, 1991, 2376, 2641},
+  { 1292, 1665, 1991, 2375, 2640},
+  { 1292, 1664, 1990, 2374, 2640},
+  { 1292, 1664, 1990, 2374, 2639},  // n = 80
+
+  { 1292, 1664, 1990, 2373, 2638},
+  { 1292, 1664, 1989, 2373, 2637},
+  { 1292, 1663, 1989, 2372, 2636},
+  { 1292, 1663, 1989, 2372, 2636},
+  { 1292, 1663, 1988, 2371, 2635},
+
+  { 1291, 1663, 1988, 2370, 2634},
+  { 1291, 1663, 1988, 2370, 2634},
+  { 1291, 1662, 1987, 2369, 2633},
+  { 1291, 1662, 1987, 2369, 2632},
+  { 1291, 1662, 1987, 2368, 2632},  //  n = 90
+
+  { 1291, 1662, 1986, 2368, 2631},
+  { 1291, 1662, 1986, 2368, 2630},
+  { 1291, 1661, 1986, 2367, 2630},
+  { 1291, 1661, 1986, 2367, 2629},
+  { 1291, 1661, 1985, 2366, 2629},
+
+  { 1290, 1661, 1985, 2366, 2628},
+  { 1290, 1661, 1985, 2365, 2627},
+  { 1290, 1661, 1984, 2365, 2627},
+  { 1290, 1660, 1984, 2365, 2626},
+  { 1290, 1660, 1984, 2364, 2626}  //  n = 100
+
+120	1289	1658	1980	2358	2617
+10000	1282	1645	1960	2327	2576  //  effectively infinity.
+*/
+
+
+//  -- END OF FILE --
+
--- a/libraries/Student/examples/Student_test/Student_test.ino
+++ b/libraries/Student/examples/Student_test/Student_test.ino
@ -0,0 +1,65 @@
+//
+//    FILE: Student_test.ino
+//  AUTHOR: Rob Tillaart
+// PURPOSE: demo
+
+
+#include "Student.h"
+
+Student S;
+
+void setup(void)
+{
+  Serial.begin(115200);
+  Serial.println(__FILE__);
+  Serial.print("STUDENT_LIB_VERSION: ");
+  Serial.println(STUDENT_LIB_VERSION);
+  Serial.println();
+
+  S.reset();
+  S.add(12.4);
+  S.add(11.8);
+  S.add(12.0);
+  S.add(11.7);
+  S.add(12.1);
+  S.add(12.3);
+  S.add(11.9);
+  S.add(11.6);
+  S.add(11.9);
+  S.add(12.3);
+
+  //  for (int i = 0; i < 10; i++)
+  //  {
+  //    S.add(i);
+  //  }
+  Serial.print("Size:\t");
+  Serial.println(S.getSize());
+  Serial.print("Count:\t");
+  Serial.println(S.getCount());
+
+  Serial.print("mean:\t");
+  Serial.println(S.mean(), 3);
+  Serial.print("var:\t");
+  Serial.println(S.variance(), 3);
+  Serial.print("dev:\t");
+  Serial.println(S.deviation(), 3);
+  Serial.print("E dev:\t");
+  Serial.println(S.estimatedDeviation(), 3);
+  Serial.print("MeanLow:\t");
+  Serial.println(S.meanLower(95), 3);
+  Serial.print("MeanUp:\t");
+  Serial.println(S.meanUpper(95), 3);
+
+
+  Serial.println("\ndone...");
+}
+
+
+void loop(void)
+{
+}
+
+
+
+
+// -- END OF FILE --
--- a/libraries/Student/keywords.txt
+++ b/libraries/Student/keywords.txt
@ -0,0 +1,26 @@
+# Syntax Colouring Map For Student
+
+# Data types (KEYWORD1)
+Student	KEYWORD1
+
+# Methods and Functions (KEYWORD2)
+
+getSize	KEYWORD2
+getCount	KEYWORD2
+reset	KEYWORD2
+add	KEYWORD2
+
+mean	KEYWORD2
+variance	KEYWORD2
+deviation	KEYWORD2
+estimatedDeviation	KEYWORD2
+
+intervalDelta	KEYWORD2
+meanLower	KEYWORD2
+meanUpper	KEYWORD2
+
+
+# Constants (LITERAL1)
+STUDENT_LIB_VERSION	LITERAL1
+
+
--- a/libraries/Student/library.json
+++ b/libraries/Student/library.json
@ -0,0 +1,23 @@
+{
+  "name": "Student",
+  "keywords": "probability, statistic",
+  "description": "Arduino library for Student or T-distribution math.",
+  "authors":
+  [
+    {
+      "name": "Rob Tillaart",
+      "email": "Rob.Tillaart@gmail.com",
+      "maintainer": true
+    }
+  ],
+  "repository":
+  {
+    "type": "git",
+    "url": "https://github.com/RobTillaart/Student.git"
+  },
+  "version": "0.1.0",
+  "license": "MIT",
+  "frameworks": "*",
+  "platforms": "*",
+  "headers": "Student.h"
+}
--- a/libraries/Student/library.properties
+++ b/libraries/Student/library.properties
@ -0,0 +1,12 @@
+name=Student
+version=0.1.0
+author=Rob Tillaart <rob.tillaart@gmail.com>
+maintainer=Rob Tillaart <rob.tillaart@gmail.com>
+sentence=LArduino library for Student or T-distribution math.
+paragraph=probability, statistic.
+category=Data Processing
+url=https://github.com/RobTillaart/Student
+architectures=*
+includes=Student.h
+depends=
+
--- a/libraries/Student/test/unit_test_001.cpp
+++ b/libraries/Student/test/unit_test_001.cpp
@ -0,0 +1,88 @@
+//
+//    FILE: unit_test_001.cpp
+//  AUTHOR: Rob Tillaart
+//    DATE: 2024-07-22
+// PURPOSE: unit tests for the Student library
+//          https://github.com/RobTillaart/Student
+//          https://github.com/Arduino-CI/arduino_ci/blob/master/REFERENCE.md
+//
+
+// supported assertions
+// ----------------------------
+// assertEqual(expected, actual)
+// assertNotEqual(expected, actual)
+// assertLess(expected, actual)
+// assertMore(expected, actual)
+// assertLessOrEqual(expected, actual)
+// assertMoreOrEqual(expected, actual)
+// assertTrue(actual)
+// assertFalse(actual)
+// assertNull(actual)
+
+
+#include <ArduinoUnitTests.h>
+
+#include "Arduino.h"
+#include "Student.h"
+
+
+unittest_setup()
+{
+    fprintf(stderr, "STUDENT_LIB_VERSION: %s\n", (char *) STUDENT_LIB_VERSION);
+}
+
+
+unittest_teardown()
+{
+}
+
+
+unittest(test_constants)
+{
+  assertEqual(20, STUDENT_MAX_SIZE);
+}
+
+
+unittest(test_constructor)
+{
+  Student S;
+
+  assertEqual(20, S.getSize());
+  assertEqual(00, S.getCount());
+}
+
+
+unittest(test_all)
+{
+  Student S;
+
+  S.reset();
+  assertEqual(0, S.getCount());
+
+  S.add(12.4);
+  S.add(11.8);
+  S.add(12.0);
+  S.add(11.7);
+  S.add(12.1);
+  S.add(12.3);
+  S.add(11.9);
+  S.add(11.6);
+  S.add(11.9);
+  S.add(12.3);
+
+  assertEqual(10, S.getCount());
+  assertEqualFloat(12.0, S.mean(), 0.001);
+  assertEqualFloat(0.073, S.variance(), 0.001);
+  assertEqualFloat(0.271, S.deviation(), 0.001);
+  assertEqualFloat(0.086, S.estimatedDeviation(), 0.001);
+
+  assertEqualFloat(11.809, S.meanLower(95), 0.001);
+  assertEqualFloat(12.191, S.meanUpper(95), 0.001);
+}
+
+
+unittest_main()
+
+
+//  -- END OF FILE --
+