4.1 KiB
moduloMap
Arduino library for the moduloMap class.
Description
The moduloMap is an experimental library that optimizes modular mapping.
How do I define modular mapping?
Imagine the mapping of all real numbers on a subset in a modular way. Imagine the real number line rolled around a defined circle with a minimum and maximum value. After one rotation the numbers mapped to start over again.
E.g. moduloMap(7, 13) maps all the real numbers to the interval [7; 13> modulo 6.
So the numbers 7..13 do not change as they are already within the range 7-13. The number 6 is mapped on 12, 5 on 11, 4 on 10, .. 1 on 7, 0 on 12 -1 on 11 etc. Similar the numbers in between e.g 5.5 is mapped on 11.5
Note: there is no scaling.
Other name might be circular mapping, although it might be any shape. (for now circles is complex enough)
Applications
- modular mapping of rotations to angles.
This can be on 0-360 degrees or 0-2PI radians or -180-180 degrees or even -90..270 degrees. - hoist math
Imagine a hoist, that needs to roll up / roll off a long rope around a cylinder. - wire cutter
Determine the length of a wire for a wire cutter by moving it between two wheels with known circumference. - math fun
Related
Other mapping libraries
- https://github.com/RobTillaart/FastMap
- https://github.com/RobTillaart/Gamma
- https://github.com/RobTillaart/map2colour
- https://github.com/RobTillaart/moduloMap
- https://github.com/RobTillaart/MultiMap
Interface
#include "moduloMap.h"
- moduloMap() constructor.
- bool begin(float minimum, float maximum) define the range the numbers should be mapped to. Returns true if minimum < maximum, false otherwise.
- float map(float value) actual mapping of a value to a number within the range.
- float rotations(float value) how many ranges (maximum - minimum) fit in a given length.
Think of it as how many rotations must a hoist must make to "free" a rope of given length. Or how many rotations a hoist has to make to roll up a rope of given length. This includes the minimum that already has rolled off / should stay rolled off.
Get internal parameters (for debug)
- float getMinimum() idem.
- float getMaximum() idem.
- float getRange() idem.
Performance
Tested with moduloMap_performance.ino on AVR.
| version | 1000 x map |
|---|---|
| 0.1.0 | 44120 us |
| 0.1.1 | 36340 us |
Operation
The examples show the basic working of the functions.
Future
Must
- elaborate documentation
- add examples
Should
- move code to .cpp file
Could
- are there other than circular modulo?
- triangular, square, pentagram, fractal?
- increasing length per rotation (complex)
- add begin(float radius)
- assumes circle from 0..max
Wont
Support
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Thank you,