An implementation for the “Arduino map” function in Dart, which allows numbers to be remapped from one range to another.


remap method:

Remaps a number from one range to another. That is, a value of fromLow would get mapped to toLow, a value of fromHigh to toHigh, and values in-between to values in-between.

It does not constrain the values to the provided range, because out-of-range values are sometimes intended and useful. Use the remapAndClamp method if you wish for the values to be constrained.

Note that the “lower bounds” of either range may be larger or smaller than the “upper bounds” so the remap() method may be used to reverse a range of numbers, for example:

final reversedX = x.remap(1, 50, 50, 1);

The method also handles negative numbers well, so that this example

final y = x.remap(1, 50, 50, -100);

is also valid.

remapAndClamp method:

Same as remap, however, the result is being constrained to the range toLow-toHigh.

For instance, the following code returns 1:

150.remapAndClamp(0, 100, 0, 1)

Note that toLow may be greater than toHigh, so the following code

final y = x.remapAndClamp(0, 100, 100, 0);


Integer-only methods:

Both the remap and the remapAndClamp offer integer-only versions of themselves (named remapInt and remapAndClampInt respectively). These work the same as their num counterparts, however, their returned value is guaranteed to be an integer.

isWithinRange method:

Returns whether a number is within a given range.

Getting started

  1. Add the package as a dependency to your pubspec.yaml.
  2. Import the library:
import 'package:num_remap/num_remap.dart';


The library acts as an extension to the num and int types. You can use its methods as follows:

import 'package:num_remap/num_remap.dart';


final someDouble = 0.5;
final remappedDouble = someDouble.remap(0.0, 1.0, -100.0, 100.0);