Plot Type: Marker - ScottPlot 4.1 Cookbook

This page contains recipes for the Marker category.
Visit the Cookbook Home Page to view all cookbook recipes.
Generated by ScottPlot 4.1.67 on 8/13/2023

Marker

You can place individual markers anywhere on the plot.

var plt = new ScottPlot.Plot(600, 400);

var colormap = ScottPlot.Drawing.Colormap.Turbo;
Random rand = new(0);
for (int i = 0; i < 100; i++)
{
    plt.AddMarker(
        x: rand.NextDouble(),
        y: rand.NextDouble(),
        size: 5 + rand.NextDouble() * 20,
        shape: Marker.Random(rand),
        color: colormap.RandomColor(rand));
}

plt.SaveFig("marker_quickstart.png");

Draggable Marker

A special type of marker exists which allows dragging with the mouse.

var plt = new ScottPlot.Plot(600, 400);

plt.AddSignal(ScottPlot.DataGen.Sin(51));
plt.AddSignal(ScottPlot.DataGen.Cos(51));

var myDraggableMarker = new ScottPlot.Plottable.DraggableMarkerPlot()
{
    X = 25,
    Y = .57,
    Color = Color.Magenta,
    MarkerShape = MarkerShape.filledDiamond,
    MarkerSize = 15,
    Text = "drag the point!",
};

myDraggableMarker.TextFont.Size = 16;

plt.Add(myDraggableMarker);

plt.SaveFig("marker_draggable.png");

Draggable Marker Snap

This example shows how to add a draggable marker which is constrained to positions defined by an array of X/Y pairs.

var plt = new ScottPlot.Plot(600, 400);

// create random data and display it with a scatter plot
double[] xs = DataGen.Consecutive(50);
double[] ys = DataGen.Random(new Random(0), 50);
plt.AddScatter(xs, ys, label: "data");

// place the marker at the first data point
var marker = plt.AddMarkerDraggable(xs[0], ys[0], MarkerShape.filledDiamond, 15, Color.Magenta);

// constrain snapping to the array of data points
marker.DragSnap = new ScottPlot.SnapLogic.Nearest2D(xs, ys);

plt.Legend();

plt.SaveFig("marker_draggableinvector.png");

Labeled Marker

Markers have an optional text label.

var plt = new ScottPlot.Plot(600, 400);

plt.AddSignal(DataGen.Sin(51));

var marker = plt.AddMarker(35, 0.6);
marker.Text = "Interesting Point";
marker.TextFont.Color = Color.Magenta;
marker.TextFont.Alignment = Alignment.UpperCenter;
marker.TextFont.Size = 28;

plt.SaveFig("marker_labeled.png");

Marker Line Width

Markers have options that can be customized, such as line width.

var plt = new ScottPlot.Plot(600, 400);

double[] ys1 = DataGen.Sin(30);
var cmap1 = ScottPlot.Drawing.Colormap.Viridis;

double[] ys2 = DataGen.Cos(30);
var cmap2 = ScottPlot.Drawing.Colormap.Turbo;

for (int i = 0; i < ys1.Length; i++)
{
    double frac = i / (ys1.Length - 1f);

    var circle = plt.AddMarker(i, ys1[i]);
    circle.MarkerShape = MarkerShape.openCircle;
    circle.MarkerSize = i + 5;
    circle.MarkerLineWidth = 1 + i / 2;
    circle.MarkerColor = cmap1.GetColor(1 - frac, .8);

    var triangle = plt.AddMarker(i, ys2[i]);
    triangle.MarkerShape = MarkerShape.openTriangleUp;
    triangle.MarkerSize = i + 5;
    triangle.MarkerLineWidth = 1 + i / 4;
    triangle.MarkerColor = cmap2.GetColor(frac, .8);
}

plt.Margins(.2, .2);

plt.SaveFig("marker_linewidth.png");

Circle Marker

Circles can be added anywhere on the plot. If a line style is used, a custom pattern should be created.

var plt = new ScottPlot.Plot(600, 400);

// create a custom pattern (defining dash and space lengths)
List<float> patternLengths = new();
for (int i = 0; i < 20; i++)
{
    patternLengths.Add(1f); // dash
    patternLengths.Add(.5f); // space
    patternLengths.Add(.25f); // dot
    patternLengths.Add(.5f); // space
}

// normalize the lengths so the total pattern length is 1
float totalPatternLength = patternLengths.Sum();
float[] pattern = patternLengths.Select(x => x / totalPatternLength).ToArray();

// apply the custom pattern
ScottPlot.LineStylePatterns.Custom = pattern;

// plot a circle using the custom pattern
plt.AddCircle(x: 7, y: 13, radius: 5, lineWidth: 3, lineStyle: LineStyle.Custom);

plt.SaveFig("marker_Circle.png");