Logarithmic Scale
The [ObservableObject], [ObservableProperty] and [ICommand] attributes come from the
CommunityToolkit.Mvvm package, you can read more about it
here.
This web site wraps every sample using a UserControl instance, but LiveCharts controls can be used inside any container.
View model
using System;
using CommunityToolkit.Mvvm.ComponentModel;
using LiveChartsCore;
using LiveChartsCore.SkiaSharpView;
namespace ViewModelsSamples.Axes.Logarithmic;
public partial class ViewModel : ObservableObject
{
// base 10 log, change the base if you require it.
// or use any custom scale the logic is the same.
private static readonly int s_logBase = 10;
public ISeries[] Series { get; set; } =
{
new LineSeries<LogarithmicPoint>
{
Mapping = (logPoint, chartPoint) =>
{
// for the x coordinate, we use the X property of the LogaritmicPoint instance
chartPoint.SecondaryValue = logPoint.X;
// but for the Y coordinate, we will map to the logarithm of the value
chartPoint.PrimaryValue = Math.Log(logPoint.Y, s_logBase); // mark
},
Values = new LogarithmicPoint[]
{
new() { X = 1, Y = 10 },
new() { X = 2, Y = 100 },
new() { X = 3, Y = 1000 },
new() { X = 4, Y = 10000 },
new() { X = 5, Y = 100000 },
new() { X = 6, Y = 1000000 },
new() { X = 7, Y = 10000000 }
}
}
};
public Axis[] YAxes { get; set; } =
{
new Axis
{
// forces the step of the axis to be at least 1
MinStep = 1,
// converts the log scale back for the label
Labeler = value => Math.Pow(s_logBase, value).ToString() // mark
}
};
}
LogarithmicPoint.cs
namespace ViewModelsSamples.Axes.Logarithmic;
public class LogarithmicPoint
{
public double X { get; set; }
public double Y { get; set; }
}
XAML
<UserControl x:Class="WPFSample.Axes.Logarithmic.View"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:lvc="clr-namespace:LiveChartsCore.SkiaSharpView.WPF;assembly=LiveChartsCore.SkiaSharpView.WPF"
xmlns:vms="clr-namespace:ViewModelsSamples.Axes.Logarithmic;assembly=ViewModelsSamples">
<UserControl.DataContext>
<vms:ViewModel/>
</UserControl.DataContext>
<lvc:CartesianChart
Series="{Binding Series}"
DrawMarginFrame="{Binding Frame}"
XAxes="{Binding XAxes}"
YAxes="{Binding YAxes}">
</lvc:CartesianChart>
</UserControl>
