Plotting in C# (Part 4 - ScottPlot)

ScottPlot is an open-source, .NET-based charting library designed for creating high-performance, interactive plots in applications like WinForms, WPF, and Console apps. Its simplicity, lightweight design, and focus on performance make it a great choice for developers working with scientific or large-scale data visualizations.

Some characteristics of ScottPlot are:

• Ease of Use: Simple API to generate plots with minimal setup.
• High Performance: Handles large datasets efficiently (e.g., millions of data points).
• Customization: Fully customizable charts (colors, markers, titles, legends, axes, etc.).
• Interactivity: Built-in support for zooming, panning, and interacting with plots.
• Live/Streaming Data: Real-time data plotting capabilities.

Setting up ScottPlot in a WinForms application

Setting up ScottPlot in a WinForms application is straightforward. Here’s how you can do it:

• Install ScottPlot via NuGet by searching for ScottPlot.WinForms and then installing the backage
• Add a ScottPlot Control to Your Form: Open a WinForm and add FormsPlot to your form
• Setting up the plot in code: After adding the FormsPlot control, you can configure it in the code-behind file.

using System;
using System.Windows.Forms;

namespace ScottPlotWinFormsExample
{
     public partial class Form1 : Form
     {
          public Form1()
          {
              InitializeComponent();
          }

          private void Form1_Load(object sender, EventArgs e)
          {
              // Generate some sample data
              double[] xs = DataGen.Consecutive(100);  // X data
              double[] ys = DataGen.Sin(100);      // Y data

              // Add a scatter plot
              formsPlot1.Plot.AddScatter(xs, ys);

              // Add titles and labels
              formsPlot1.Plot.Title("Sample Chart");
              formsPlot1.Plot.XLabel("X-Axis");
              formsPlot1.Plot.YLabel("Y-Axis");

              // Refresh the plot to display it
              formsPlot1.Refresh();
          }
     }
}        

ScottPlot versions

The latest version of ScottPlot at the time of writing this article is 5.0.46. Version 5 and higher is not fully compatible with lower versions. ScottPlot has evolved significantly, with v5.x introducing a new architecture and new features compared to the v4.x series.?

Here are some of the most important features of v5.x compare to v4.x:

Redesigned API:

• More intuitive and consistent.
• Fluent interface for chaining methods.
• Enhanced code readability and maintainability.

Improved Performance:

• Optimized for large datasets.
• Handles live/streaming data more efficiently.

Better Interactivity:

• More robust zooming, panning, and interaction features.
• Enhanced event system for handling clicks, hovers, and drag events.

Legend Improvements:

• Highly customizable legend positioning and formatting.
• Clickable legends to toggle series visibility.

Rendering Pipeline:

• Fully rewritten for smoother animations and better scaling across high-DPI monitors.

New Features:

• Plot styling improvements.
• Simplified handling of axes and layout management.
• Customizable tick marks and grid styles.

Showing and Formatting the Legend

Show Legend: The legend is automatically enabled if multiple plots are added with labels.

Customize Legend: The legend can easily customized.

formsPlot1.Plot.Legend(location: ScottPlot.Alignment.UpperRight);
formsPlot1.Plot.Legend(fontSize: 14, bold: true);
formsPlot1.Refresh();        

Chart Customization

Adding a Title

formsPlot1.Plot.Title("Sample Chart", size: 20);
formsPlot1.Plot.XLabel("X-Axis", size: 16);
formsPlot1.Plot.YLabel("Y-Axis", size: 16);

formsPlot1.Refresh();        

Customizing Colors and Style

var scatter = formsPlot1.Plot.AddScatter(xs, ys);
scatter.Color = System.Drawing.Color.Red;
scatter.LineWidth = 2;
formsPlot1.Plot.Style(ScottPlot.Style.Light1);  // Predefined styles
formsPlot1.Refresh();        

Working with Axes

Format Axes

formsPlot1.Plot.SetAxisLimits(xMin: 0, xMax: 10, yMin: -5, yMax: 5);
formsPlot1.Plot.XAxis.ManualTickSpacing(1);  // Set custom tick spacing
formsPlot1.Plot.XAxis.TickLabelStyle(fontSize: 14);
formsPlot1.Refresh();        

Horizontal Time Axis

var dates = Enumerable.Range(0, 10).Select(i => DateTime.Now.AddDays(i)).ToArray();
double[] xs = dates.Select(x => x.ToOADate()).ToArray();
double[] ys = new double[xs.Length]; // Some Y data

formsPlot1.Plot.AddScatter(xs, ys);
formsPlot1.Plot.XAxis.DateTimeFormat(true);  // Enable date formatting
formsPlot1.Refresh();        

Handling Large Data

ScottPlot provides tools to handle large datasets (e.g., decimation).

Using SignalPlot for Large Data:

var signal = formsPlot1.Plot.AddSignal(data);
formsPlot1.Refresh();        

Real-Time/Streaming Data

var scatter = formsPlot1.Plot.AddScatter(xs, ys);
// Updating in a Timer

Timer timer = new Timer { Interval = 100 }; // Refresh every 100ms
timer.Tick += (s, e) =>
{
     xs = xs.Skip(1).Concat(new[] { xs.Last() + 1 }).ToArray(); // Shift Xs
     ys = ys.Skip(1).Concat(new[] { Random.Shared.NextDouble() }).ToArray(); // Shift Ys
     scatter.Update(xs, ys);
     formsPlot1.Refresh();
};

timer.Start();        

Interactions (Zoom, Pan, Toggle Series, Get Data)

Zoom and Pan: Enabled by default in WinForms via mouse scroll and drag.

Turn On/Off Series

scatter.IsVisible = false; // Hide series
formsPlot1.Refresh();        

Get Point Value by Mouse

formsPlot1.MouseMove += (s, e) =>
{
     (double mouseX, double mouseY) = formsPlot1.GetMouseCoordinates();
     lblCoords.Text = $"Mouse: {mouseX}, {mouseY}";
};        

Annotations

formsPlot1.Plot.AddText("Hello", x: 5, y: 5);
formsPlot1.Refresh();        

Comparison between LiveCharts2, OxyPlot and ScottPlot

Here's a detailed comparison of LiveCharts2, OxyPlot, and ScottPlot based on their latest versions. Note that these are just my personal idea:

Conclusion

ScottPlot is an excellent choice for developers looking for a lightweight, high-performance charting solution, especially for scientific or engineering applications. It’s particularly strong when handling large datasets or real-time data, I’ve personally tested it for more than 2 million points and it still worked perfectly. Maybe some features are still not implemented or need improvement but, ScottPlot remains a highly capable and efficient tool for most charting needs.

#plot #scottplot #csharp #dotnet