smoothie

Description:

smoothie

smoothie #
A simple curve smoothing utility. Turn a set of your data points into a smooth Bézier curve in one line of code.
Usage #
Let's say you have some arbitrary data (a list of points):
var _originalDataSeries = <Point>[
Point(0, 5),
Point(3, 15),
Point(5, 10),
Point(6, 6),
Point(9, 13),
];
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Define a desired number of samples in the resulting curve:
int _sampleCount = 100;
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Import smoothie:
import 'package:smoothie/smoothie.dart';
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Create a smooth curve using the getSampledCurveFromPoints extension function on your original data:
List<Point<num>> _sampledCurve = _originalDataSeries.smooth(_sampleCount);
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See oversampling in action:

Full example using the charts_flutter package:
import 'dart:math';

import 'package:charts_flutter/flutter.dart' as charts;
import 'package:flutter/material.dart';
import 'package:smoothie/smoothie.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Smoothie Demo',
theme: ThemeData(
primarySwatch: Colors.teal,
),
home: SmoothieHomePage(),
);
}
}

class SmoothieHomePage extends StatefulWidget {
SmoothieHomePage({Key? key}) : super(key: key);

@override
_SmoothieHomePageState createState() => _SmoothieHomePageState();
}

class _SmoothieHomePageState extends State<SmoothieHomePage> {
int _samplingPointCount = 0;

var _originalDataSeries = <Point>[
Point(0, 5),
Point(2, 15),
Point(3, 10),
Point(8, 6),
Point(9, 13),
];

@override
void initState() {
super.initState();
_samplingPointCount = _originalDataSeries.length;
}

void _incrementCounter() {
setState(() {
_samplingPointCount++;
});
}

void _decrementCounter() {
setState(() {
if (_samplingPointCount > _originalDataSeries.length)
_samplingPointCount--;
});
}

@override
Widget build(BuildContext context) {
var series = [
new charts.Series(
domainFn: (Point chartData, _) => chartData.x,
measureFn: (Point chartData, _) => chartData.y,
colorFn: (Point point, _) => charts.MaterialPalette.teal.shadeDefault,
id: 'Example Series',
data: _originalDataSeries.smooth(
_samplingPointCount,
),
),
];

var chart = new charts.LineChart(
series,
animate: false,
defaultRenderer: new charts.LineRendererConfig(
includeArea: true,
),
);

return Scaffold(
appBar: AppBar(
title: Text("Smoothie Demo"),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'The smooth curve now has $_samplingPointCount points.',
),
Container(
height: 200,
child: chart,
),
],
),
),
floatingActionButton: Row(
mainAxisAlignment: MainAxisAlignment.end,
children: <Widget>[
FloatingActionButton(
onPressed: _decrementCounter,
tooltip: 'Decrement',
child: Icon(Icons.remove),
),
FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
],
));
}
}
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If you want to run the example as is and you are using null safety, you have to pass --no-sound-null-safety to the build command as the current version of charts_flutter does not yet support null safety:
cd example
flutter run --no-sound-null-safety
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