update library.json, readme, license, minor edits (#5)

* update library.json, readme, license, minor edits

Author: RobTillaart

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2011-2021 Rob Tillaart
+Copyright (c) 2011-2022 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

MultiMap.h

@@ -2,45 +2,47 @@
 //
 //    FILE: MultiMap.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.4
+// VERSION: 0.1.5
 //    DATE: 2011-01-26
 // PURPOSE: Arduino library for fast non-linear mapping or interpolation of values
 //     URL: https://github.com/RobTillaart/MultiMap
 //     URL: http://playground.arduino.cc/Main/MultiMap
 //
 //  HISTORY:
 //  0.0.1   2011-01-26 initial version (see forum)
-//  .....
+//  .....   eons passed ...
 //  0.1.0   2015-03-29
 //  0.1.1   2020-04-09
 //  0.1.2   2020-06-19  fix library.json
-//  0.1.3   2021-01-02  add arduino-CI 
-//  0.1.4   2021-05-27  fix arduino-lint
+//  0.1.3   2021-01-02  add Arduino-CI 
+//  0.1.4   2021-05-27  fix Arduino-lint
+//  0.1.5   2021-12-22  update library.json, readme, license, minor edits
 
 
-#define MULTIMAP_LIB_VERSION        (F("0.1.4"))
+#define MULTIMAP_LIB_VERSION                (F("0.1.5"))
 
 
 #include "Arduino.h"
 
+
 // note: the in array should have increasing values
 template<typename T>
-T multiMap(T val, T* _in, T* _out, uint8_t size)
+T multiMap(T value, T* _in, T* _out, uint8_t size)
 {
     // take care the value is within range
-    // val = constrain(val, _in[0], _in[size-1]);
-    if (val <= _in[0]) return _out[0];
-    if (val >= _in[size-1]) return _out[size-1];
+    // value = constrain(value, _in[0], _in[size-1]);
+    if (value <= _in[0]) return _out[0];
+    if (value >= _in[size-1]) return _out[size-1];
 
     // search right interval
-    uint8_t pos = 1;  // _in[0] allready tested
-    while(val > _in[pos]) pos++;
+    uint8_t pos = 1;  // _in[0] already tested
+    while(value > _in[pos]) pos++;
 
     // this will handle all exact "points" in the _in array
-    if (val == _in[pos]) return _out[pos];
+    if (value == _in[pos]) return _out[pos];
 
     // interpolate in the right segment for the rest
-    return (val - _in[pos-1]) * (_out[pos] - _out[pos-1]) / (_in[pos] - _in[pos-1]) + _out[pos-1];
+    return (value - _in[pos-1]) * (_out[pos] - _out[pos-1]) / (_in[pos] - _in[pos-1]) + _out[pos-1];
 }
 
 
@@ -50,42 +52,42 @@ T multiMap(T val, T* _in, T* _out, uint8_t size)
 // note: the in array should have increasing values
 
 template<typename T>
-T multiMap(T val, T* _in, T* _out, uint8_t size)
+T multiMap(T value, T* _in, T* _out, uint8_t size)
 {
   static T lastvalue = -1;
   static T cache = -1;  
 
-  if (val == lastvalue)
+  if (value == lastvalue)
   {
     return cache;
   }
-  lastvalue = val;
+  lastvalue = value;
 
   // take care the value is within range
-  // val = constrain(val, _in[0], _in[size-1]);
-  if (val <= _in[0])
+  // value = constrain(value, _in[0], _in[size-1]);
+  if (value <= _in[0])
   {
     cache = _out[0];
   }
-  else if (val >= _in[size-1])
+  else if (value >= _in[size-1])
   {
     cache = _out[size-1];
   }
   else
   {
     // search right interval; index 0 _in[0] already tested
     uint8_t pos = 1;  
-    while(val > _in[pos]) pos++;
+    while(value > _in[pos]) pos++;
     
     // this will handle all exact "points" in the _in array
-    if (val == _in[pos]) 
+    if (value == _in[pos]) 
     {
       cache = _out[pos];
     }
     else
     {
       // interpolate in the right segment for the rest
-      cache = (val - _in[pos-1]) * (_out[pos] - _out[pos-1]) / (_in[pos] - _in[pos-1]) + _out[pos-1];
+      cache = (value - _in[pos-1]) * (_out[pos] - _out[pos-1]) / (_in[pos] - _in[pos-1]) + _out[pos-1];
     }
   }
   return cache;
@@ -94,3 +96,4 @@ T multiMap(T val, T* _in, T* _out, uint8_t size)
 
 
 // -- END OF FILE --
+

README.md

@@ -15,7 +15,8 @@ Arduino library for fast non-linear mapping or interpolation of values
 
 In Arduino applications often the value of a sensor is mapped upon a more
 usable value. E.g. the value of analogRead() is mapped onto 0 .. 5.0 Volt.
-This is done by the map function which does a linear interpolation. This means
+This is done by the map function which does a linear interpolation. 
+This means in code:
 
 ```cpp
     output = C1 + input * C2
@@ -28,14 +29,15 @@ two variables runtime from two given mappings.
     output = map(input, I1, I2, O1, O2):
 ```
 
-In many cases when there is no linear mapping possible, as the 'points' are not on a single line.
-One needs non-linear math to calculate the output, **Multimap()** just does that.
+In many cases when there is no linear mapping possible, as the 'points' are not on a single straight line.
+One needs non-linear math to calculate the output, **Multimap()** just simulates that.
 
-**out = Multimap(value, input, output, size)** needs two equal sized arrays of reference 'points', **input\[\]** and **output\[\]**, it looks up the 
+**out = Multimap(value, input, output, size)** needs two equal sized arrays of reference 'points', 
+**input\[\]** and **output\[\]**, it looks up the 
 input value in the input\[\] array and if needed it linear interpolates between two
 points of the output\[\] array. 
 
-- The **input\[\]** array must have increasing values,
+- The **input\[\]** array must have increasing values, 
 there is no such restriction for the **output\[\]** array.
 - **Multimap()** automatically constrains the output to the first and last value in the **output\[\]** array.
 
@@ -52,7 +54,10 @@ Please note the fail example as this shows that in the intern math overflow can
 - Investigate class implementation for performance / footprint
 - flag if input value was "IN_MIN" <  input < "IN_MAX", 
   now it is constrained without user being informed.
+- extend unit tests
+
+
+**wont**
 - should the lookup tables be merged into one array of pairs?
-  - you cannot reuse e.g. the input array then.
-- 
-- 
+  - you cannot reuse e.g. the input array then. (memory footprint)
+

examples/multimap_NTC/multimap_NTC.ino

@@ -1,7 +1,6 @@
 //
 //    FILE: multimap_NTC.ino
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.1
 // PURPOSE: demo
 //    DATE: 2020-04-09
 //    (c) : MIT
@@ -90,3 +89,4 @@ float val(int sensorValueA1)
 
 
 // -- END OF FILE --
+

examples/multimap_NTC_int_FAIL/multimap_NTC_int_FAIL.ino

@@ -1,16 +1,15 @@
 //
 //    FILE: multimap_NTC_int_FAIL.ino
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.1
 // PURPOSE: demo of faulty optimizing 
 //    DATE: 2020-04-09
 //    (c) : MIT
 //
-
+//
 // NOTE:
 // use integers instead of floats to minimize RAM. uses ~320 bytes PROGMEM ~120 bytes RAM less on UNO than float version
 //
-// this example is added to show how to reduce memory but  also how it can FAIL due to math overflow
+// this example is added to show how to reduce memory but also how it can FAIL due to math overflow
 // E.g. see around 196-200; 340-400
 // to prevent this one must have more values which increases the memory usage again.
 // 
@@ -92,3 +91,4 @@ float val(int sensorValueA1)
 
 
 // -- END OF FILE --
+

examples/multimap_distance/multimap_distance.ino

@@ -1,7 +1,6 @@
 //
 //    FILE: multimap_distance.ino
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.1
 // PURPOSE: demo
 //    DATE: 2020-04-09
 //
@@ -49,3 +48,4 @@ float sharp2cm(int val)
 
 
 // -- END OF FILE --
+

examples/multimap_functions/multimap_functions.ino

@@ -1,7 +1,6 @@
 //
 //    FILE: multimap_functions.ino
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.1
 // PURPOSE: demo (use serial plotter)...
 //    DATE: 2020-04-09
 //    (c) : MIT
@@ -55,7 +54,7 @@ void test_normal_distribution()
 
 void test_sinus()
 {
-  // one sinus wave, amplitudo 1023
+  // one sinus wave, amplitude 1023
   long sinus[] = {0, 316, 601, 827, 972, 1023, 972, 827, 601, 316, 0, -316, -601, -827, -972, -1023, -972, -827, -601, -316, 0 }; //21
   long in[21];
   for (int i = 0; i < 21; i++) in[i] = round(i * 1000.0 / 20);
@@ -138,3 +137,4 @@ void test_sawtooth()
 
 
 // -- END OF FILE --
+

examples/multimap_timing/multimap_timing.ino

@@ -1,7 +1,6 @@
 //
 //    FILE: multimap_timing.ino
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.1
 // PURPOSE: demo
 //    DATE: 2020-04-09
 //    (c) : MIT
@@ -54,3 +53,4 @@ void loop()
 
 
 // -- END OF FILE --
+

library.json

@@ -15,7 +15,7 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/MultiMap.git"
   },
-  "version": "0.1.4",
+  "version": "0.1.5",
   "license": "MIT",
   "frameworks": "arduino",
   "platforms": "*",

library.properties

@@ -1,5 +1,5 @@
 name=MultiMap
-version=0.1.4
+version=0.1.5
 author=Rob Tillaart <[email protected]>
 maintainer=Rob Tillaart <[email protected]>
 sentence=Library for fast non-linear interpolation by means of two arrays.