Small signed drift

Create a console project, add the ChartForgeX package, and replace Program.cs with this source. Run it to write SVG, PNG and HTML with the default system fonts.

For the same typography as the gallery, download the gallery-font recipe and copy the gallery’s fonts directory beside your program.

using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using ChartForgeX.Core;
using ChartForgeX.Primitives;
using ChartForgeX.Rendering;
using ChartForgeX.Themes;
using ChartForgeX.Topology;
using ChartForgeX.Typography;
using ChartForgeX.VisualArtifacts;
using ChartForgeX.VisualBlocks;

var mode = VisualThemeMode.Light;
var theme = VisualTheme.Graphite();
var model = TrendLineRecipe.Create("precision", mode);
var context = new VisualRenderContext(
    new VisualLayoutOptions(new VisualSize(800, 440)), theme, mode,
    new VisualFrame("Small signed drift", "Measured differences stay in their original units", showLegend: null, showSurface: false));
var prepared = model.Prepare(context);
File.WriteAllText("visual.svg", prepared.ToSvg());
File.WriteAllBytes("visual.png", prepared.ToPng());
File.WriteAllText("visual.html", prepared.ToArtifact("example", VisualArtifactKind.Chart).ToHtmlPage());

/// <summary>Builds a least-squares trend while retaining the observations used to fit it.</summary>
public static class TrendLineRecipe {
    /// <summary>Creates the selected trend example, including the small-drift precision case.</summary>
    public static Chart Create(string variant = "wide", VisualThemeMode mode = VisualThemeMode.Light) {
        if (variant is not ("wide" or "compact" or "sparse" or "options" or "compact-options" or "precision" or "compact-precision"))
            throw new ArgumentOutOfRangeException(nameof(variant));
        if (variant is "precision" or "compact-precision") {
            var drift = ChartSeries.CreateTrendLine(new ChartSeriesId("least-squares-drift"), "Least-squares drift",
                Enumerable.Range(0, 4096).Select(index => new ChartPoint(index % 10 + .5, index % 7 - 3)));
            return Chart.Create().WithXAxis("Measurement").WithYAxis("Fitted drift").AddSeries(drift);
        }
        var points = Enumerable.Range(1, 6).Where(index => variant != "sparse" || index is 1 or 3 or 6)
            .Select(index => new ChartPoint(index, 20 + index * 7 % 29, variant == "sparse" && index == 6)).ToArray();
        var observations = ChartSeries.CreateScatter(new ChartSeriesId("observations"), "Observations", points);
        var trend = ChartSeries.CreateTrendLine(new ChartSeriesId("least-squares-trend"), "Least-squares trend", points);
        return Chart.Create().WithXLabels("Mon", "Tue", "Wed", "Thu", "Fri", "Sat").AddSeries(observations).AddSeries(trend)
            .WithValueFormat(ChartValueFormat.Number("0.##", CultureInfo.InvariantCulture));
    }
}

using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using ChartForgeX.Core;
using ChartForgeX.Primitives;
using ChartForgeX.Rendering;
using ChartForgeX.Themes;
using ChartForgeX.Topology;
using ChartForgeX.Typography;
using ChartForgeX.VisualArtifacts;
using ChartForgeX.VisualBlocks;

var mode = VisualThemeMode.Dark;
var theme = VisualTheme.Graphite();
var model = TrendLineRecipe.Create("precision", mode);
var context = new VisualRenderContext(
    new VisualLayoutOptions(new VisualSize(800, 440)), theme, mode,
    new VisualFrame("Small signed drift", "Measured differences stay in their original units", showLegend: null, showSurface: false));
var prepared = model.Prepare(context);
File.WriteAllText("visual.svg", prepared.ToSvg());
File.WriteAllBytes("visual.png", prepared.ToPng());
File.WriteAllText("visual.html", prepared.ToArtifact("example", VisualArtifactKind.Chart).ToHtmlPage());

/// <summary>Builds a least-squares trend while retaining the observations used to fit it.</summary>
public static class TrendLineRecipe {
    /// <summary>Creates the selected trend example, including the small-drift precision case.</summary>
    public static Chart Create(string variant = "wide", VisualThemeMode mode = VisualThemeMode.Light) {
        if (variant is not ("wide" or "compact" or "sparse" or "options" or "compact-options" or "precision" or "compact-precision"))
            throw new ArgumentOutOfRangeException(nameof(variant));
        if (variant is "precision" or "compact-precision") {
            var drift = ChartSeries.CreateTrendLine(new ChartSeriesId("least-squares-drift"), "Least-squares drift",
                Enumerable.Range(0, 4096).Select(index => new ChartPoint(index % 10 + .5, index % 7 - 3)));
            return Chart.Create().WithXAxis("Measurement").WithYAxis("Fitted drift").AddSeries(drift);
        }
        var points = Enumerable.Range(1, 6).Where(index => variant != "sparse" || index is 1 or 3 or 6)
            .Select(index => new ChartPoint(index, 20 + index * 7 % 29, variant == "sparse" && index == 6)).ToArray();
        var observations = ChartSeries.CreateScatter(new ChartSeriesId("observations"), "Observations", points);
        var trend = ChartSeries.CreateTrendLine(new ChartSeriesId("least-squares-trend"), "Least-squares trend", points);
        return Chart.Create().WithXLabels("Mon", "Tue", "Wed", "Thu", "Fri", "Sat").AddSeries(observations).AddSeries(trend)
            .WithValueFormat(ChartValueFormat.Number("0.##", CultureInfo.InvariantCulture));
    }
}