Logarithmic Scale

View model

using System;
using CommunityToolkit.Mvvm.ComponentModel;
using LiveChartsCore;
using LiveChartsCore.SkiaSharpView;
using LiveChartsCore.SkiaSharpView.Painting;
using SkiaSharp;

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>
        {
            // for the x coordinate, we use the X property
            // and for the Y coordinate, we will map it to the logarithm of the value
            Mapping = (logPoint, index) => new(logPoint.X, Math.Log(logPoint.Y, s_logBase)),
            Values = new LogarithmicPoint[]
            {
                new() { X = 1, Y = 1 },
                new() { X = 2, Y = 10 },
                new() { X = 3, Y = 100 },
                new() { X = 4, Y = 1000 },
                new() { X = 5, Y = 10000 },
                new() { X = 6, Y = 100000 },
                new() { X = 7, Y = 1000000 },
                new() { X = 8, Y = 10000000 }
            }
        }
    };

    public Axis[] YAxes { get; set; } =
    {
        new LogaritmicAxis(s_logBase)
        {
            SeparatorsPaint = new SolidColorPaint
            {
                Color = SKColors.Black.WithAlpha(100),
                StrokeThickness = 1,
            },
            SubseparatorsPaint = new SolidColorPaint
            {
                Color = SKColors.Black.WithAlpha(50),
                StrokeThickness = 0.5f
            },
            SubseparatorsCount = 9,
        }
    };
}

LogarithmicPoint.cs

namespace ViewModelsSamples.Axes.Logarithmic;

public class LogarithmicPoint
{
    public double X { get; set; }
    public double Y { get; set; }
}

using Eto.Forms;
using LiveChartsCore.SkiaSharpView.Eto;
using ViewModelsSamples.Axes.Logarithmic;

namespace EtoFormsSample.Axes.Logarithmic;

public class View : Panel
{
    private readonly CartesianChart cartesianChart;

    public View()
    {
        var viewModel = new ViewModel();

        cartesianChart = new CartesianChart
        {
            Series = viewModel.Series,
            YAxes = viewModel.YAxes,
        };

        Content = cartesianChart;
    }
}

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