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ScottPlot 5 for C# WinForms

Overview

ScottPlot 5.1.58 is a free .NET plotting library. In WinForms, use the FormsPlot control (formsPlot1).

NuGet packages required:

• ScottPlot (core library)
• ScottPlot.WinForms (WinForms control)

Essential using:

using System.Linq;      // for Enumerable.Range / .Select in math-generated data
using ScottPlot;
using ScottPlot.WinForms;

Every code block must end with formsPlot1.Refresh(); to render the plot.

Quick Reference

Scatter vs Signal vs SignalConst

• Scatter: Paired X/Y data, hundreds of points, flexible X spacing
• Signal: Y data + fixed sample period, millions of points, high framerate
• SignalConst: Constant data, hundreds of millions of points

Plot Types & Code Examples

All examples below have been compiled and visually verified on ScottPlot 5.1.58.

Signal Plot

// Basic signal
double[] values = Generate.Sin(51);
formsPlot1.Plot.Add.Signal(values);
formsPlot1.Refresh();

Signal with offset, color, legend, and axis labels (verified):

var sig1 = formsPlot1.Plot.Add.Signal(Generate.Sin(51));
sig1.LegendText = "Sin";
sig1.LineWidth = 2;
sig1.Color = Colors.Blue;

var sig2 = formsPlot1.Plot.Add.Signal(Generate.Cos(51));
sig2.LegendText = "Cos";
sig2.LineWidth = 2;
sig2.Color = Colors.Red;
sig2.Data.YOffset = 0.5;
sig2.Data.XOffset = 5;

formsPlot1.Plot.Title("Signal Plot Demo");
formsPlot1.Plot.XLabel("Sample Index");
formsPlot1.Plot.YLabel("Amplitude");
formsPlot1.Plot.ShowLegend(Alignment.UpperRight);
formsPlot1.Refresh();

SignalXY Plot

double[] xs = Generate.Consecutive(100);
double[] ys = Generate.RandomWalk(100);
formsPlot1.Plot.Add.SignalXY(xs, ys);
formsPlot1.Refresh();

Scatter Plot

// Basic scatter
double[] xs = { 1, 2, 3, 4, 5 };
double[] ys = { 1, 4, 9, 16, 25 };
formsPlot1.Plot.Add.Scatter(xs, ys);
formsPlot1.Refresh();

Scatter with Smooth, ScatterPoints, custom ticks & rotated labels (verified):

double[] xs = Generate.Consecutive(51);
double[] ys1 = Generate.Sin(51);
double[] ys2 = Generate.Cos(51);

var sp1 = formsPlot1.Plot.Add.Scatter(xs, ys1);
sp1.LegendText = "Smooth Sin";
sp1.Smooth = true;
sp1.LineWidth = 2;

var sp2 = formsPlot1.Plot.Add.ScatterPoints(xs, ys2);
sp2.LegendText = "Cos Points";
sp2.MarkerSize = 6;

// Custom tick labels
double[] tickPos = { 0, 10, 20, 30, 40, 50 };
string[] tickLabels = { "Start", "P1", "P2", "P3", "P4", "End" };
formsPlot1.Plot.Axes.Bottom.SetTicks(tickPos, tickLabels);

// Rotated tick labels
formsPlot1.Plot.Axes.Bottom.TickLabelStyle.Rotation = -30;
formsPlot1.Plot.Axes.Bottom.TickLabelStyle.Alignment = Alignment.MiddleRight;

formsPlot1.Plot.Title("Scatter Plot with Smooth & Custom Ticks");
formsPlot1.Plot.ShowLegend();
formsPlot1.Refresh();

Scatter with lines only:

var sp = formsPlot1.Plot.Add.ScatterLine(xs, ys);
formsPlot1.Refresh();

Bar Plot

// Simple bar chart
double[] values = { 5, 10, 7, 13, 25, 60 };
formsPlot1.Plot.Add.Bars(values);
formsPlot1.Plot.Axes.Margins(bottom: 0);
formsPlot1.Refresh();

Bar[] with Palette colors, error bars, manual ticks & rotated labels (verified):

ScottPlot.Palettes.Category10 palette = new();

ScottPlot.Bar[] bars = new ScottPlot.Bar[]
{
    new() { Position = 1, Value = 25, FillColor = palette.GetColor(0), Error = 3 },
    new() { Position = 2, Value = 40, FillColor = palette.GetColor(1), Error = 5 },
    new() { Position = 3, Value = 30, FillColor = palette.GetColor(2), Error = 2 },
    new() { Position = 4, Value = 55, FillColor = palette.GetColor(3), Error = 4 },
    new() { Position = 5, Value = 20, FillColor = palette.GetColor(4), Error = 3 },
};

formsPlot1.Plot.Add.Bars(bars);

Tick[] ticks = new Tick[]
{
    new(1, "Alpha"), new(2, "Beta"), new(3, "Gamma"),
    new(4, "Delta"), new(5, "Epsilon"),
};
formsPlot1.Plot.Axes.Bottom.TickGenerator = new ScottPlot.TickGenerators.NumericManual(ticks);
formsPlot1.Plot.Axes.Bottom.TickLabelStyle.Rotation = 45;
formsPlot1.Plot.Axes.Bottom.TickLabelStyle.Alignment = Alignment.MiddleLeft;
formsPlot1.Plot.Axes.Margins(bottom: 0);

formsPlot1.Plot.Title("Bar Plot with Error Bars & Custom Ticks");
formsPlot1.Plot.YLabel("Value");
formsPlot1.Refresh();

Horizontal bars:

var barPlot = formsPlot1.Plot.Add.Bars(values);
barPlot.Horizontal = true;
formsPlot1.Refresh();

Pie Chart (verified)

double[] values = { 3, 2, 8, 4, 8, 2 };
var pie = formsPlot1.Plot.Add.Pie(values);
pie.ExplodeFraction = 0.1;

formsPlot1.Plot.Title("Pie Chart Demo");
formsPlot1.Plot.Axes.Frameless();
formsPlot1.Plot.HideGrid();
formsPlot1.Refresh();

Heatmap (verified)

double[,] data = Generate.Sin2D(width: 40, height: 30);
var hm = formsPlot1.Plot.Add.Heatmap(data);
hm.Colormap = new ScottPlot.Colormaps.Turbo();

formsPlot1.Plot.Add.ColorBar(hm);
formsPlot1.Plot.Title("Heatmap with Turbo Colormap");
formsPlot1.Refresh();

Candlestick / OHLC

List<ScottPlot.OHLC> prices = new();
// populate OHLC data...
var candle = formsPlot1.Plot.Add.Candlestick(prices);
formsPlot1.Plot.Axes.DateTimeTicksBottom();
formsPlot1.Refresh();

Box Plot

List<ScottPlot.Box> boxes = new()
{
    new() { Position = 1, BoxMin = 3, BoxMax = 7, WhiskerMin = 1, WhiskerMax = 9, BoxMiddle = 5 },
    new() { Position = 2, BoxMin = 5, BoxMax = 8, WhiskerMin = 3, WhiskerMax = 10, BoxMiddle = 6 },
};
var bp = formsPlot1.Plot.Add.Boxes(boxes);
formsPlot1.Refresh();

DataLogger — real-time growing data (verified)

DataLogger accumulates an ever-growing list of (X, Y) pairs. Best for data that arrives continuously and needs to be reviewed in full (think oscilloscope / data recorder).

In WinForms, call logger.Add(...) inside a Timer.Tick event handler and call formsPlot1.Refresh() to update the display.

Quickstart — add Y values (X auto-increments by 1):

var logger = formsPlot1.Plot.Add.DataLogger();
logger.ViewFull();       // auto-expand axis to show all data

// In Timer.Tick:
logger.Add(newValue);    // X auto-increments; or: logger.Add(x, y)
formsPlot1.Refresh();

Add data with explicit X/Y coordinates:

var logger = formsPlot1.Plot.Add.DataLogger();
logger.ViewFull();

// Add by coordinate (explicit values)
logger.Add(new Coordinates(1.5, 0.7));
// Or with named args
logger.Add(x: 1.5, y: 0.7);
// Or bulk arrays
logger.Add(xs: new double[]{1, 2, 3}, ys: new double[]{0.1, 0.5, 0.3});
// Or a collection of Y values (X auto-increments)
logger.Add(ys: new double[]{0.1, 0.5, 0.3});
formsPlot1.Refresh();

Period — set X spacing to represent real time:

var logger = formsPlot1.Plot.Add.DataLogger();
logger.Period = 0.01;    // 100 Hz: each sample = 0.01 s apart
logger.ViewFull();
formsPlot1.Plot.XLabel("Time (s)");

// In Timer.Tick:
logger.Add(newSensorValue);
formsPlot1.Refresh();

View modes — controlling which data is visible:

var logger = formsPlot1.Plot.Add.DataLogger();

// Show all data (auto-expand axis)
logger.ViewFull();

// Jump: axis jumps when new data runs off screen
logger.ViewJump(width: 100, paddingFraction: 0.1);

// Slide: axis slides continuously as new data arrives
logger.ViewSlide(width: 100);
formsPlot1.Refresh();

Styling:

var logger = formsPlot1.Plot.Add.DataLogger();
logger.ViewFull();

logger.Color      = Colors.Crimson;
logger.LineWidth  = 2;
logger.LegendText = "Sensor A";
logger.MarkerSize  = 4;
logger.MarkerShape = MarkerShape.FilledCircle;

formsPlot1.Plot.ShowLegend();
formsPlot1.Refresh();

Multiple DataLoggers (multi-channel):

var logger1 = formsPlot1.Plot.Add.DataLogger();
logger1.LegendText = "Channel A";
logger1.Color = Colors.Blue;
logger1.ViewFull();

var logger2 = formsPlot1.Plot.Add.DataLogger();
logger2.LegendText = "Channel B";
logger2.Color = Colors.Red;
logger2.ViewFull();

// In Timer.Tick:
logger1.Add(valueA);
logger2.Add(valueB);
formsPlot1.Plot.ShowLegend();
formsPlot1.Refresh();

DataLogger key properties & methods:

DataStreamer — real-time fixed-length buffer (verified)

DataStreamer maintains a fixed-length circular buffer. New data shifts in from one end and old data is discarded. Best for oscilloscope-style displays where only the latest N samples matter.

In WinForms, call streamer.Add(...) in a Timer.Tick handler and call formsPlot1.Refresh(). Check streamer.HasNewData to skip unnecessary refreshes.

Quickstart:

var streamer = formsPlot1.Plot.Add.DataStreamer(200); // buffer: 200 points
streamer.ViewScrollLeft(); // newest data on the right

// In Timer.Tick:
streamer.Add(newValue);
formsPlot1.Refresh();

View modes:

var streamer = formsPlot1.Plot.Add.DataStreamer(200);

// Newest data on right (continuously shifts left)
streamer.ViewScrollLeft();

// Newest data on left (continuously shifts right)
streamer.ViewScrollRight();

// Oscilloscope wipe — new data overwrites old data left-to-right
streamer.ViewWipeRight(blankFraction: 0.1); // 10% blank gap at write head

// Wipe right-to-left
streamer.ViewWipeLeft();

formsPlot1.Refresh();

FillY — fill above/below a baseline:

var streamer = formsPlot1.Plot.Add.DataStreamer(200);
streamer.ViewScrollLeft();

streamer.FillY           = true;
streamer.FillYValue      = 0;                           // baseline Y
streamer.FillYAboveColor = Colors.Green.WithAlpha(.3);  // above baseline
streamer.FillYBelowColor = Colors.Red.WithAlpha(.3);    // below baseline

formsPlot1.Refresh();

Period — display real-time X axis:

var streamer = formsPlot1.Plot.Add.DataStreamer(200);
streamer.Period = 0.005;  // 200 Hz: 5 ms per sample
streamer.ViewScrollLeft();
formsPlot1.Plot.XLabel("Time (s)");
formsPlot1.Refresh();

Multiple DataStreamers:

var s1 = formsPlot1.Plot.Add.DataStreamer(200);
s1.LegendText = "Sin"; s1.Color = Colors.Blue; s1.ViewScrollLeft();

var s2 = formsPlot1.Plot.Add.DataStreamer(200);
s2.LegendText = "Cos"; s2.Color = Colors.Red; s2.ViewScrollLeft();

// In Timer.Tick:
s1.Add(sinValue);
s2.Add(cosValue);
formsPlot1.Plot.ShowLegend();
formsPlot1.Refresh();

HasNewData — skip refresh when no new data:

// In Timer.Tick (optimization for high-frequency timers):
// Always Add first, then conditionally Refresh:
streamer.Add(newValue);
if (streamer.HasNewData)   // true until next Render clears the flag
    formsPlot1.Refresh();

// Or, if data is produced by a background thread:
// (background thread calls streamer.Add; Timer only refreshes)
if (streamer.HasNewData)
    formsPlot1.Refresh();

DataStreamer key properties & methods:

Lines & Markers (verified)

// Horizontal / Vertical lines
var hLine = formsPlot1.Plot.Add.HorizontalLine(0.5);
hLine.Color = Colors.Red;
hLine.LineWidth = 2;

var vLine = formsPlot1.Plot.Add.VerticalLine(25);
vLine.Color = Colors.Green;
vLine.LineWidth = 2;

// Horizontal / Vertical spans
var hSpan = formsPlot1.Plot.Add.HorizontalSpan(10, 20);
hSpan.FillColor = Colors.Yellow.WithAlpha(40);
formsPlot1.Plot.Add.VerticalSpan(10, 30);

// Circle / Ellipse
var circle = formsPlot1.Plot.Add.Circle(25, 0, 5);
circle.FillColor = Colors.Magenta.WithAlpha(50);
circle.LineColor = Colors.Magenta;
formsPlot1.Plot.Add.Ellipse(0, 0, radiusX: 5, radiusY: 3);

// Polygon
Coordinates[] pts = { new(0,0), new(1,2), new(2,0) };
formsPlot1.Plot.Add.Polygon(pts);

// Arrow
formsPlot1.Plot.Add.Arrow(new Coordinates(0, 0), new Coordinates(1, 1));

formsPlot1.Refresh();

Text & Annotation (verified)

// Text (positioned in data coordinates)
var txt = formsPlot1.Plot.Add.Text("Hello!", x: 5, y: 0.8);
txt.LabelStyle.FontSize = 20;

// Annotation (positioned in fractional figure space, stays fixed when panning)
var ann = formsPlot1.Plot.Add.Annotation("Top-Left Note");
ann.Alignment = Alignment.UpperLeft;

formsPlot1.Refresh();

Tooltip (verified)

A tooltip displays a text bubble with a tail pointing to a specific coordinate. Add.Tooltip(tip, text, label) — tip is the pointed coordinate, label is where the bubble sits.

Quickstart:

double[] ys = Generate.Sin(50);
var sig = formsPlot1.Plot.Add.Signal(ys);
sig.MaximumMarkerSize = 20;

Coordinates tip   = new(25, ys[25]);      // point to highlight
Coordinates label = tip.WithDelta(8, .7); // bubble offset from tip
formsPlot1.Plot.Add.Tooltip(tip, "Special Point", label);
formsPlot1.Refresh();

Font & color styling:

Coordinates tip   = new(25, 0.5);         // use a fixed coordinate
Coordinates label = tip.WithDelta(8, .7);
var tt = formsPlot1.Plot.Add.Tooltip(tip, "Special Point", label);

// Font
tt.LabelFontSize  = 18;
tt.LabelBold      = true;
tt.LabelFontColor = Colors.Yellow;

// Background & border
tt.FillColor = Colors.Blue;
tt.LineColor = Colors.Navy;
tt.LineWidth = 3;
formsPlot1.Refresh();

Tail width control:

// TailWidthPercentage: 0.0 (needle) → 1.0 (full-width base)
Coordinates tip   = new(25, 0.5);
Coordinates label = tip.WithDelta(8, .7);
var tt = formsPlot1.Plot.Add.Tooltip(tip, "Wide Tail", label);
tt.TailWidthPercentage = 0.5;  // default ~0.3
formsPlot1.Refresh();

Auto-angle — bubble direction adjusts automatically:

// Tooltip tail direction is computed from the relative position of tip vs. label.
// Place the label at any offset and the tail will point correctly.
for (int i = 0; i < 360; i += 30)
{
    Coordinates tip   = new(0, 0);
    PolarCoordinates polar = new(1, Angle.FromDegrees(i));
    Coordinates label = polar.ToCartesian();
    var tt = formsPlot1.Plot.Add.Tooltip(tip, $"{i}°", label);
    tt.FillColor     = Colormap.Default.GetColor(i, 360).Lighten(0.5);
    tt.LineColor     = Colormap.Default.GetColor(i, 360);
    tt.LabelBold     = true;
    tt.LabelFontColor = Colormap.Default.GetColor(i, 360).Darken(0.5);
}
formsPlot1.Plot.Axes.SetLimits(-1.5, 1.5, -1.5, 1.5);
formsPlot1.Refresh();

Multiple tooltips on a scatter chart:

double[] xs = Generate.Consecutive(20);
double[] ys = Generate.Sin(20);
formsPlot1.Plot.Add.Scatter(xs, ys);

int[] highlightIdx    = { 5, 10, 15 };
string[] messages     = { "Min", "Zero", "Max" };
for (int i = 0; i < highlightIdx.Length; i++)
{
    int idx           = highlightIdx[i];
    Coordinates tip   = new(xs[idx], ys[idx]);
    Coordinates label = tip.WithDelta(1.5, .3);
    var tt = formsPlot1.Plot.Add.Tooltip(tip, messages[i], label);
    tt.FillColor = Colors.White;
    tt.LineColor = Colors.DarkGray;
    tt.LineWidth = 1.5f;
}
formsPlot1.Refresh();

Tooltip key properties:

tip.WithDelta(dx, dy) is a convenience method on Coordinates that returns new Coordinates(tip.X + dx, tip.Y + dy) — useful for placing the bubble near the tip with a fixed offset.

Marker (verified)

Markers are symbols placed at a specific location in coordinate space.

Single marker:

// Place individual markers at specific coordinates
formsPlot1.Plot.Add.Marker(25, .5);
formsPlot1.Plot.Add.Marker(35, .6);
formsPlot1.Plot.Add.Marker(45, .7);
formsPlot1.Refresh();

Many markers (batch) — Add.Markers returns a Markers plottable for further configuration:

double[] xs = Generate.Consecutive(51);
double[] sin = Generate.Sin(51);
double[] cos = Generate.Cos(51);

var sinMarkers = formsPlot1.Plot.Add.Markers(xs, sin, MarkerShape.OpenCircle, 15, Colors.Green);
sinMarkers.LegendText = "Sin Markers";

var cosMarkers = formsPlot1.Plot.Add.Markers(xs, cos, MarkerShape.FilledDiamond, 10, Colors.Magenta);
cosMarkers.LegendText = "Cos Markers";

formsPlot1.Plot.ShowLegend();
formsPlot1.Refresh();

Marker with legend:

var marker = formsPlot1.Plot.Add.Marker(25, .5);
marker.LegendText = "Marker";
formsPlot1.Plot.ShowLegend();
formsPlot1.Refresh();

MarkerStyle customization (FillColor, OutlineColor, LineColor):

var mp = formsPlot1.Plot.Add.Marker(x: 5, y: 3);
mp.MarkerStyle.Shape = MarkerShape.FilledDiamond;
mp.MarkerStyle.Size = 20;

// Filled shape styling
mp.MarkerStyle.FillColor = Colors.Gold.WithAlpha(.5);
mp.MarkerStyle.OutlineColor = Colors.DarkGoldenrod;
mp.MarkerStyle.OutlineWidth = 2;

// Line-based shape styling
mp.MarkerStyle.LineWidth = 2f;
mp.MarkerStyle.LineColor = Colors.DarkGoldenrod;
formsPlot1.Refresh();

Scatter with custom MarkerShape:

double[] xs = Generate.Consecutive(51);
double[] ys = Generate.Sin(51);

var sp = formsPlot1.Plot.Add.Scatter(xs, ys);
sp.MarkerSize = 15;
sp.MarkerShape = MarkerShape.OpenTriangleUp;
sp.Color = Colors.Navy;
formsPlot1.Refresh();

Available MarkerShape values: None, FilledCircle, OpenCircle, FilledSquare, OpenSquare, FilledTriangleUp, OpenTriangleUp, FilledTriangleDown, OpenTriangleDown, FilledDiamond, OpenDiamond, Eks, Cross, VerticalBar, HorizontalBar, TriUp, TriDown, Asterisk, HashTag, OpenCircleWithDot, OpenCircleWithCross, OpenCircleWithEks, CircleWithLineLeft, CircleWithLineRight, TriangleWithLineLeft, TriangleWithLineRight

填充型 vs 线条型属性说明：

• 填充型（FilledCircle, FilledSquare, FilledTriangleUp/Down, FilledDiamond）：使用 FillColor、OutlineColor、OutlineWidth。
• 线条型（OpenCircle, OpenSquare, OpenTriangleUp/Down, Eks, Cross, VerticalBar, HorizontalBar 等）：使用 LineColor、LineWidth，FillColor 不起作用。

FillY — Area Between Curves (verified)

double[] xs = Generate.Consecutive(51);
double[] ys1 = Generate.Sin(51);
double[] ys2 = Generate.Cos(51);
var fill = formsPlot1.Plot.Add.FillY(xs, ys1, ys2);
fill.FillColor = Colors.Blue.WithAlpha(50);
fill.LegendText = "Filled Area";

formsPlot1.Plot.Title("FillY: Area Between Sin & Cos");
formsPlot1.Plot.ShowLegend();
formsPlot1.Refresh();

Polar Axis (verified)

A polar axis uses spokes and concentric circles to render a polar coordinate system. Use polarAxis.GetCoordinates(radius, degrees) to convert polar → Cartesian, then plot normally.

Important: PolarAxisSpoke and PolarAxisCircle are in the ScottPlot namespace (not ScottPlot.Plottables).

Quickstart — scatter data on polar axis:

var polarAxis = formsPlot1.Plot.Add.PolarAxis();

IColormap colormap = new ScottPlot.Colormaps.Turbo();
foreach (double degrees in Generate.Range(0, 360, 10))
{
    double radius = degrees / 360.0;  // normalized 0..1
    Coordinates pt = polarAxis.GetCoordinates(radius, degrees);
    var marker = formsPlot1.Plot.Add.Marker(pt);
    marker.Color = colormap.GetColor(radius);
}
formsPlot1.Refresh();

Rotation and Clockwise direction:

var polarAxis = formsPlot1.Plot.Add.PolarAxis();
polarAxis.Rotation = Angle.FromDegrees(90);  // offset 0° spoke to top

// Clockwise (e.g. compass/bearing displays)
polarAxis.Clockwise = true;
polarAxis.Rotation = Angle.FromDegrees(-90);
formsPlot1.Refresh();

Arrows from center to polar coordinates:

PolarCoordinates[] points = new[]
{
    new PolarCoordinates(10, Angle.FromDegrees(15)),
    new PolarCoordinates(20, Angle.FromDegrees(120)),
    new PolarCoordinates(30, Angle.FromDegrees(240)),
};

var polarAxis = formsPlot1.Plot.Add.PolarAxis(radius: 30);
polarAxis.Circles.ForEach(x => x.LinePattern = LinePattern.Dotted);
polarAxis.Spokes.ForEach(x => x.LinePattern = LinePattern.Dotted);

IPalette palette = new ScottPlot.Palettes.Category10();
Coordinates center = polarAxis.GetCoordinates(0, 0);
for (int i = 0; i < points.Length; i++)
{
    Coordinates tip = polarAxis.GetCoordinates(points[i]);
    var arrow = formsPlot1.Plot.Add.Arrow(center, tip);
    arrow.ArrowLineWidth = 0;
    arrow.ArrowFillColor = palette.GetColor(i).WithAlpha(.7);
}
formsPlot1.Refresh();

Styling spokes and circles:

var polarAxis = formsPlot1.Plot.Add.PolarAxis();

// Style spokes (straight lines from center)
var radialPalette = new ScottPlot.Palettes.Category10();
for (int i = 0; i < polarAxis.Spokes.Count; i++)
{
    polarAxis.Spokes[i].LineColor = radialPalette.GetColor(i).WithAlpha(.5);
    polarAxis.Spokes[i].LineWidth = 4;
    polarAxis.Spokes[i].LabelStyle.ForeColor = radialPalette.GetColor(i);
    polarAxis.Spokes[i].LabelStyle.FontSize = 16;
    polarAxis.Spokes[i].LabelStyle.Bold = true;
}

// Style circles (concentric rings)
var circularColormap = new ScottPlot.Colormaps.Rain();
for (int i = 0; i < polarAxis.Circles.Count; i++)
{
    double fraction = (double)i / (polarAxis.Circles.Count - 1);
    polarAxis.Circles[i].LineColor = circularColormap.GetColor(fraction).WithAlpha(.5);
    polarAxis.Circles[i].LineWidth = 2;
    polarAxis.Circles[i].LinePattern = LinePattern.Dashed;
}
formsPlot1.Refresh();

Background fill:

var polarAxis = formsPlot1.Plot.Add.PolarAxis();
polarAxis.FillColor = Colors.Blue.WithAlpha(.2);
formsPlot1.Refresh();

Custom spoke labels:

var polarAxis = formsPlot1.Plot.Add.PolarAxis();
string[] labels = { "Alpha", "Beta", "Gamma", "Delta", "Epsilon" };
polarAxis.SetSpokes(labels, length: 1.1);  // length is fraction of radius
formsPlot1.Refresh();

Tick (circle) labels + custom spoke count:

var polarAxis = formsPlot1.Plot.Add.PolarAxis();
polarAxis.Rotation = Angle.FromDegrees(-90);

double[] tickPositions = { 5, 10, 15, 20 };
string[] tickLabels = { "A", "B", "C", "D" };
polarAxis.SetCircles(tickPositions, tickLabels);
polarAxis.SetSpokes(count: 5, length: 22, degreeLabels: false);
formsPlot1.Refresh();

Manual spoke/circle geometry with individual styling:

var polarAxis = formsPlot1.Plot.Add.PolarAxis();

// PolarAxisSpoke and PolarAxisCircle are in ScottPlot namespace
polarAxis.Spokes.Clear();
polarAxis.Spokes.Add(new ScottPlot.PolarAxisSpoke(Angle.FromDegrees(0),  0.5));
polarAxis.Spokes.Add(new ScottPlot.PolarAxisSpoke(Angle.FromDegrees(45), 0.75));
polarAxis.Spokes.Add(new ScottPlot.PolarAxisSpoke(Angle.FromDegrees(90), 1.0));

polarAxis.Circles.Clear();
polarAxis.Circles.Add(new ScottPlot.PolarAxisCircle(0.5));
polarAxis.Circles.Add(new ScottPlot.PolarAxisCircle(0.75));
polarAxis.Circles.Add(new ScottPlot.PolarAxisCircle(1.0));

ScottPlot.Palettes.Category10 pal = new();
for (int i = 0; i < 3; i++)
{
    polarAxis.Spokes[i].LineColor  = pal.GetColor(i).WithAlpha(.5);
    polarAxis.Circles[i].LineColor = pal.GetColor(i).WithAlpha(.5);
    polarAxis.Spokes[i].LineWidth  = 2 + i * 2;
    polarAxis.Circles[i].LineWidth = 2 + i * 2;
}
formsPlot1.Refresh();

Radar chart using PolarAxis + Polygon:

string[] labels = { "Speed", "Power", "Accuracy", "Stamina", "Defense" };
var polarAxis = formsPlot1.Plot.Add.PolarAxis();
polarAxis.SetSpokes(labels, 1.1);
polarAxis.SetCircles(5, 4);  // (maximumRadius, count)

double maxRadius = 5.0;
double[] p1Values = { 4.2, 3.8, 4.5, 3.0, 4.0 };
double[] p2Values = { 3.5, 4.8, 3.2, 4.5, 3.8 };
int n = labels.Length;

var p1Coords = new List<Coordinates>();
var p2Coords = new List<Coordinates>();
for (int i = 0; i < n; i++)
{
    double deg = 360.0 / n * i;
    p1Coords.Add(polarAxis.GetCoordinates(p1Values[i] / maxRadius, deg));
    p2Coords.Add(polarAxis.GetCoordinates(p2Values[i] / maxRadius, deg));
}
p1Coords.Add(p1Coords[0]);  // close polygon
p2Coords.Add(p2Coords[0]);

var poly1 = formsPlot1.Plot.Add.Polygon(p1Coords.ToArray());
poly1.FillColor = Colors.Blue.WithAlpha(40);
poly1.LineColor = Colors.Blue;
poly1.LineWidth = 2;

var poly2 = formsPlot1.Plot.Add.Polygon(p2Coords.ToArray());
poly2.FillColor = Colors.Red.WithAlpha(40);
poly2.LineColor = Colors.Red;
poly2.LineWidth = 2;

formsPlot1.Plot.Title("Radar Chart");
formsPlot1.Refresh();

PolarAxis key properties & methods:

Radar Plot (verified)

Add.Radar() creates a dedicated radar/spider chart plottable backed by an internal PolarAxis.

Critical rule: Add.Radar() starts with 0 spokes and 0 circles. You must call SetSpokes before adding any RadarSeries, and the Values array length must equal the spoke count. Use SetCircles(maxValue, N) to add concentric ring ticks.

Quickstart — single series:

var radar = formsPlot1.Plot.Add.Radar();
// SetSpokes: count + length (= max data value); SetCircles: same max + ring count
radar.PolarAxis.SetSpokes(count: 5, length: 5.0);
radar.PolarAxis.SetCircles(5.0, 5);

radar.Series.Add(new ScottPlot.RadarSeries()
{
    Values    = new double[] { 5, 3, 4, 2, 5 },
    LegendText = "Score",
    FillColor = Colors.Blue.WithAlpha(.4),
    LineColor = Colors.Blue,
    LineWidth = 2,
});

formsPlot1.Plot.ShowLegend();
formsPlot1.Refresh();

Multiple series with custom spoke labels:

var radar = formsPlot1.Plot.Add.Radar();
string[] labels = { "Speed", "Power", "Accuracy", "Stamina", "Defense" };
radar.PolarAxis.SetSpokes(labels, length: 5.0);
radar.PolarAxis.SetCircles(5.0, 5);

radar.Series.Add(new ScottPlot.RadarSeries()
{
    Values    = new double[] { 4.2, 3.8, 4.5, 3.0, 4.0 },
    LegendText = "Player 1",
    FillColor = Colors.Blue.WithAlpha(.3),
    LineColor = Colors.Blue,
    LineWidth = 2,
});
radar.Series.Add(new ScottPlot.RadarSeries()
{
    Values    = new double[] { 3.5, 4.8, 3.2, 4.5, 3.8 },
    LegendText = "Player 2",
    FillColor = Colors.Red.WithAlpha(.3),
    LineColor = Colors.Red,
    LineWidth = 2,
});

formsPlot1.Plot.ShowLegend();
formsPlot1.Refresh();

Styling spokes and circles via PolarAxis:

var radar = formsPlot1.Plot.Add.Radar();
string[] labels = { "Speed", "Power", "Accuracy", "Stamina", "Defense" };
radar.PolarAxis.SetSpokes(labels, length: 5.0);
radar.PolarAxis.SetCircles(5.0, 5);

// Style each spoke individually
var pal = new ScottPlot.Palettes.Category10();
for (int i = 0; i < radar.PolarAxis.Spokes.Count; i++)
{
    radar.PolarAxis.Spokes[i].LineColor = pal.GetColor(i).WithAlpha(.7);
    radar.PolarAxis.Spokes[i].LabelStyle.ForeColor = pal.GetColor(i);
    radar.PolarAxis.Spokes[i].LabelStyle.Bold = true;
}

// Style circles
foreach (var circle in radar.PolarAxis.Circles)
{
    circle.LinePattern = LinePattern.Dashed;
    circle.LineColor = Colors.Gray.WithAlpha(.5);
}
formsPlot1.Refresh();

Hatch fill (pattern fill for a series):

var radar = formsPlot1.Plot.Add.Radar();
radar.PolarAxis.SetSpokes(count: 5, length: 5.0);
radar.PolarAxis.SetCircles(5.0, 5);

radar.Series.Add(new ScottPlot.RadarSeries()
{
    Values     = new double[] { 4.0, 3.5, 4.5, 3.0, 5.0 },
    LegendText = "Filled",
    FillColor  = Colors.Blue.WithAlpha(.3),
    LineColor  = Colors.Blue,
    LineWidth  = 2,
});
radar.Series.Add(new ScottPlot.RadarSeries()
{
    Values         = new double[] { 3.5, 4.8, 3.2, 4.5, 3.0 },
    LegendText     = "Hatched",
    FillColor      = Colors.Transparent,
    FillHatch      = new ScottPlot.Hatches.Striped(),
    FillHatchColor = Colors.Orange.WithAlpha(.7),
    LineColor      = Colors.Orange,
    LineWidth      = 2,
});

formsPlot1.Plot.ShowLegend();
formsPlot1.Refresh();

Axis above data (draw grid lines on top of fill):

var radar = formsPlot1.Plot.Add.Radar();
radar.IsAxisAboveData = true;  // set BEFORE adding series
radar.PolarAxis.SetSpokes(count: 5, length: 5.0);
radar.PolarAxis.SetCircles(5.0, 5);

radar.Series.Add(new ScottPlot.RadarSeries()
{
    Values    = new double[] { 5, 4, 3, 4, 5 },
    FillColor = Colors.Purple.WithAlpha(.4),
    LineColor = Colors.Purple,
    LineWidth = 2,
});
formsPlot1.Refresh();

RadarSeries key properties:

Radar plottable key properties:

Radial Gauge Chart (verified)

A radial gauge chart displays scalar values as arc-shaped gauges arranged concentrically. Commonly used for dashboards, KPIs, and progress indicators.

Quickstart:

double[] values = { 100, 80, 65, 45, 20 };
formsPlot1.Plot.Add.RadialGaugePlot(values);
formsPlot1.Refresh();

Palette / Colors:

// Change gauge colors via palette (applied before Add)
formsPlot1.Plot.Add.Palette = new ScottPlot.Palettes.Nord();
double[] values = { 100, 80, 65, 45, 20 };
formsPlot1.Plot.Add.RadialGaugePlot(values);
formsPlot1.Refresh();

Negative values:

formsPlot1.Plot.Add.Palette = new ScottPlot.Palettes.Nord();
double[] values = { 100, 80, -65, 45, -20 };  // negative arcs fill opposite direction
formsPlot1.Plot.Add.RadialGaugePlot(values);
formsPlot1.Refresh();

GaugeMode — Sequential (each gauge starts at tip of previous):

formsPlot1.Plot.Add.Palette = new ScottPlot.Palettes.Nord();
double[] values = { 100, 80, 65, 45, 50 };
var rg = formsPlot1.Plot.Add.RadialGaugePlot(values);
rg.GaugeMode = ScottPlot.RadialGaugeMode.Sequential;
formsPlot1.Refresh();

GaugeMode — SingleGauge (semicircle KPI-style):

formsPlot1.Plot.Add.Palette = new ScottPlot.Palettes.Nord();
double[] values = { 100, 80, 65, 45 };
var rg = formsPlot1.Plot.Add.RadialGaugePlot(values);
rg.GaugeMode    = ScottPlot.RadialGaugeMode.SingleGauge;
rg.MaximumAngle = 180;  // semicircle
rg.StartingAngle = 180; // start from West
formsPlot1.Refresh();

Angular range and direction:

formsPlot1.Plot.Add.Palette = new ScottPlot.Palettes.Nord();
double[] values = { 100, 80, 65, 45, 20 };
var rg = formsPlot1.Plot.Add.RadialGaugePlot(values);
rg.MaximumAngle  = 270;    // 270° arc instead of full circle
rg.StartingAngle = 135;    // 270 for North (default), 0 for East, 90 for South
rg.Clockwise     = false;  // counter-clockwise fill
formsPlot1.Refresh();

Labels in legend:

formsPlot1.Plot.Add.Palette = new ScottPlot.Palettes.Nord();
double[] values = { 100, 80, 65, 45, 20 };
var rg = formsPlot1.Plot.Add.RadialGaugePlot(values);
rg.Labels = new string[] { "Alpha", "Beta", "Gamma", "Delta", "Epsilon" };
formsPlot1.Plot.ShowLegend();
formsPlot1.Refresh();

Fine-tuning display:

formsPlot1.Plot.Add.Palette = new ScottPlot.Palettes.Nord();
double[] values = { 100, 80, 65, 45, 20 };
var rg = formsPlot1.Plot.Add.RadialGaugePlot(values);
rg.ShowLevels                  = true;   // show value text on each gauge
rg.LabelPositionFraction       = 0.5;    // 0 = near base, 1 = at tip
rg.FontSizeFraction            = 0.4;    // label font size relative to gauge width
rg.SpaceFraction               = 0.05;   // gap between gauges (0.2 = 20% of gauge width)
rg.BackgroundTransparencyFraction = 0.3; // 0 = opaque background ring, 1 = fully transparent
formsPlot1.Refresh();

RadialGaugePlot key properties:

Arrow (verified)

Add.Arrow() draws a coordinate-space arrow pointing from a base to a tip. Ideal for annotating key data points.

Quickstart:

double[] ys = Generate.Sin(51);
var sig = formsPlot1.Plot.Add.Signal(ys);

Coordinates arrowTip  = new(25, ys[25]);
Coordinates arrowBase = new(35, 1.3);
formsPlot1.Plot.Add.Arrow(new CoordinateLine(arrowBase, arrowTip));
formsPlot1.Refresh();

Styling (color, width):

Coordinates tip   = new(0, 0);
Coordinates base1 = new(1, 1);
var arrow = formsPlot1.Plot.Add.Arrow(new CoordinateLine(base1, tip));
arrow.ArrowFillColor = Colors.Red;      // arrowhead fill
arrow.ArrowLineColor = Colors.DarkRed;  // shaft/outline color
arrow.ArrowLineWidth = 2;               // shaft line thickness
arrow.ArrowWidth = 8;                   // shaft width (pixels)
formsPlot1.Refresh();

Arrowhead shape customization:

// Skinny needle arrowhead
var skinny = formsPlot1.Plot.Add.Arrow(
    new CoordinateLine(new Coordinates(0, 1), new Coordinates(1, 1)));
skinny.ArrowFillColor   = Colors.Green;
skinny.ArrowLineWidth   = 0;   // no shaft line
skinny.ArrowWidth       = 3;
skinny.ArrowheadLength  = 20;
skinny.ArrowheadWidth   = 7;

// Fat broad arrowhead
var fat = formsPlot1.Plot.Add.Arrow(
    new CoordinateLine(new Coordinates(0, 0), new Coordinates(1, 0)));
fat.ArrowFillColor  = Colors.Blue;
fat.ArrowLineWidth  = 0;
fat.ArrowWidth      = 18;
fat.ArrowheadLength = 20;
fat.ArrowheadWidth  = 30;
formsPlot1.Refresh();

WithDelta helper — offset arrow base from tip:

Coordinates tip   = new(25, 0.9);
Coordinates base1 = tip.WithDelta(5, 0.3);  // 5 units right, 0.3 units up
var arrow = formsPlot1.Plot.Add.Arrow(new CoordinateLine(base1, tip));
arrow.ArrowOffset = 10;  // pull tip back 10 pixels from arrowTip coordinate
formsPlot1.Refresh();

Arrow key properties:

Polygon (verified)

Add.Polygon() draws a closed filled shape from an array of coordinate vertices. Useful for highlighting regions, custom shapes, and geometric annotations.

Quickstart:

Coordinates[] coords = {
    new(0, 0), new(2, 4), new(4, 0)
};
formsPlot1.Plot.Add.Polygon(coords);
formsPlot1.Refresh();

Fill color and border:

Coordinates[] coords = {
    new(0, 0), new(1, 3), new(3, 4), new(5, 2), new(4, 0)
};
var poly = formsPlot1.Plot.Add.Polygon(coords);
poly.FillColor = Colors.Blue.WithAlpha(0.3);  // semi-transparent fill
poly.LineColor = Colors.Blue;
poly.LineWidth = 2;
formsPlot1.Refresh();

Hatch fill:

Coordinates[] coords = {
    new(0, 0), new(1, 3), new(3, 4), new(5, 2), new(4, 0)
};
var poly = formsPlot1.Plot.Add.Polygon(coords);
poly.FillColor      = Colors.LightBlue.WithAlpha(0.3);
poly.FillHatch      = new ScottPlot.Hatches.Striped(
    ScottPlot.Hatches.StripeDirection.DiagonalUp);
poly.FillHatchColor = Colors.Blue.WithAlpha(0.6);
poly.LineColor      = Colors.Blue;
formsPlot1.Refresh();

Outline only (no fill):

Coordinates[] coords = {
    new(0, 0), new(2, 4), new(4, 0)
};
var poly = formsPlot1.Plot.Add.Polygon(coords);
poly.FillColor = Colors.Transparent;  // no fill
poly.LineColor = Colors.DarkGreen;
poly.LineWidth = 3;
formsPlot1.Refresh();

Generate polygon from math (regular N-gon):

// Pentagon centered at (4, 1) with radius 1
int n = 5;
var pts = Enumerable.Range(0, n).Select(i => {
    double angle = Math.PI * 2 * i / n - Math.PI / 2;
    return new Coordinates(4 + Math.Cos(angle), 1 + Math.Sin(angle));
}).ToArray();
var pent = formsPlot1.Plot.Add.Polygon(pts);
pent.FillColor = Colors.Blue.WithAlpha(0.3);
pent.LineColor = Colors.Blue;
pent.LegendText = "Pentagon";
formsPlot1.Plot.ShowLegend();
formsPlot1.Refresh();

Polygon key properties:

Title & Labels

formsPlot1.Plot.Title("My Title");
formsPlot1.Plot.XLabel("X Axis");
formsPlot1.Plot.YLabel("Y Axis");
formsPlot1.Refresh();

Axis Limits

formsPlot1.Plot.Axes.SetLimits(xMin: -10, xMax: 60, yMin: -2, yMax: 2);
formsPlot1.Plot.Axes.AutoScale();
formsPlot1.Plot.Axes.SetLimitsY(bottom: -2, top: 2);
formsPlot1.Refresh();

DateTime Axis (verified)

DateTime[] dates = Generate.ConsecutiveDays(100);
double[] ys = Generate.RandomWalk(100);

var sp = formsPlot1.Plot.Add.Scatter(dates, ys);
sp.LineWidth = 2;
sp.LegendText = "Random Walk";

formsPlot1.Plot.Axes.DateTimeTicksBottom();
formsPlot1.Plot.Title("DateTime Axis Demo");
formsPlot1.Plot.ShowLegend();
formsPlot1.Refresh();

Multiple Y Axes (verified)

var sig1 = formsPlot1.Plot.Add.Signal(Generate.Sin(51, mult: 0.01));
var sig2 = formsPlot1.Plot.Add.Signal(Generate.Cos(51, mult: 100));
sig1.Axes.YAxis = formsPlot1.Plot.Axes.Left;
sig2.Axes.YAxis = formsPlot1.Plot.Axes.Right;

formsPlot1.Plot.Axes.Left.Label.Text = "Left Axis (small)";
formsPlot1.Plot.Axes.Left.Label.ForeColor = sig1.Color;
formsPlot1.Plot.Axes.Right.Label.Text = "Right Axis (large)";
formsPlot1.Plot.Axes.Right.Label.ForeColor = sig2.Color;

formsPlot1.Plot.Title("Multi-Axis: Dual Y Scales");
formsPlot1.Plot.ShowLegend();
formsPlot1.Refresh();

Add Extra Axes

var yAxis2 = formsPlot1.Plot.Axes.AddLeftAxis();
var sig = formsPlot1.Plot.Add.Signal(Generate.Cos(51, mult: 100));
sig.Axes.YAxis = yAxis2;
yAxis2.LabelText = "Secondary Y Axis";
formsPlot1.Refresh();

Inverted Axis

formsPlot1.Plot.Axes.SetLimitsY(bottom: 1.5, top: -1.5);
// or auto-inverted:
formsPlot1.Plot.Axes.AutoScaler.InvertedY = true;
formsPlot1.Refresh();

Square Units (circles stay circular)

formsPlot1.Plot.Axes.SquareUnits();
formsPlot1.Refresh();

Frameless

formsPlot1.Plot.Axes.Frameless();
formsPlot1.Plot.HideGrid();
formsPlot1.Refresh();

Legend

var sig1 = formsPlot1.Plot.Add.Signal(Generate.Sin());
sig1.LegendText = "Sin";
var sig2 = formsPlot1.Plot.Add.Signal(Generate.Cos());
sig2.LegendText = "Cos";
formsPlot1.Plot.ShowLegend();
// or position it:
formsPlot1.Plot.ShowLegend(Alignment.UpperRight);
formsPlot1.Refresh();

Grid Customization (verified)

// Hide grid entirely
formsPlot1.Plot.HideGrid();

// Or customize grid with fill bands:
formsPlot1.Plot.Grid.MajorLineColor = Colors.Green.WithOpacity(.3);
formsPlot1.Plot.Grid.MajorLineWidth = 2;
formsPlot1.Plot.Grid.MinorLineColor = Colors.Gray.WithOpacity(.1);
formsPlot1.Plot.Grid.MinorLineWidth = 1;

// Alternating fill bands
formsPlot1.Plot.Grid.XAxisStyle.FillColor1 = Colors.Gray.WithOpacity(0.1);
formsPlot1.Plot.Grid.XAxisStyle.FillColor2 = Colors.Gray.WithOpacity(0.2);
formsPlot1.Plot.Grid.YAxisStyle.FillColor1 = Colors.Gray.WithOpacity(0.1);
formsPlot1.Plot.Grid.YAxisStyle.FillColor2 = Colors.Gray.WithOpacity(0.2);
formsPlot1.Refresh();

Tick Customization

Custom Tick Labels

double[] tickPositions = { 10, 25, 40 };
string[] tickLabels = { "Alpha", "Beta", "Gamma" };
formsPlot1.Plot.Axes.Bottom.SetTicks(tickPositions, tickLabels);
formsPlot1.Refresh();

Manual Tick Generator (verified)

ScottPlot.TickGenerators.NumericManual ticks = new();
ticks.AddMajor(0, "zero");
ticks.AddMajor(20, "twenty");
ticks.AddMajor(50, "fifty");
ticks.AddMinor(10);
ticks.AddMinor(30);
ticks.AddMinor(40);
formsPlot1.Plot.Axes.Bottom.TickGenerator = ticks;

// Reduce Y-axis tick density
ScottPlot.TickGenerators.NumericAutomatic tickGenY = new();
tickGenY.TickDensity = 0.3;
formsPlot1.Plot.Axes.Left.TickGenerator = tickGenY;
formsPlot1.Refresh();

Rotated Tick Labels

formsPlot1.Plot.Axes.Bottom.TickLabelStyle.Rotation = -45;
formsPlot1.Plot.Axes.Bottom.TickLabelStyle.Alignment = Alignment.MiddleRight;
formsPlot1.Refresh();

Custom Tick Formatter

static string CustomFormatter(double position) => $"{position:F1} units";
ScottPlot.TickGenerators.NumericAutomatic tickGen = new() { LabelFormatter = CustomFormatter };
formsPlot1.Plot.Axes.Bottom.TickGenerator = tickGen;
formsPlot1.Refresh();

Log Scale Ticks (verified)

double[] xs = Generate.Consecutive(100);
double[] ys = Generate.NoisyExponential(100);
double[] logYs = ys.Select(Math.Log10).ToArray();
formsPlot1.Plot.Add.ScatterPoints(xs, logYs);

ScottPlot.TickGenerators.LogMinorTickGenerator minorTickGen = new();
ScottPlot.TickGenerators.NumericAutomatic tickGen = new()
{
    MinorTickGenerator = minorTickGen,
    IntegerTicksOnly = true,
    LabelFormatter = (double y) => $"{Math.Pow(10, y):N0}",
};
formsPlot1.Plot.Axes.Left.TickGenerator = tickGen;

formsPlot1.Plot.Grid.MajorLineColor = Colors.Black.WithOpacity(.15);
formsPlot1.Plot.Grid.MinorLineColor = Colors.Black.WithOpacity(.05);
formsPlot1.Plot.Grid.MinorLineWidth = 1;

formsPlot1.Plot.Title("Log Scale Y Axis");
formsPlot1.Plot.XLabel("Sample");
formsPlot1.Plot.YLabel("Value (log)");
formsPlot1.Refresh();

DateTime Fixed Interval Ticks

var dtAx = formsPlot1.Plot.Axes.DateTimeTicksBottom();
dtAx.TickGenerator = new ScottPlot.TickGenerators.DateTimeFixedInterval(
    new ScottPlot.TickGenerators.TimeUnits.Hour(), 6,
    new ScottPlot.TickGenerators.TimeUnits.Hour(), 1,
    dt => new DateTime(dt.Year, dt.Month, dt.Day));
formsPlot1.Refresh();

Styling

Colors

// Named colors
Colors.Red; Colors.Green; Colors.Blue;

// From RGB
new Color(red: 255, green: 0, blue: 0);

// From hex
new Color("#FF6600");

// From System.Drawing.Color
new Color(System.Drawing.Color.Green);

// Alpha / Opacity
Colors.Blue.WithAlpha(.5);
Colors.Red.WithOpacity(0.3);

// HSL
Color.FromHSL(hue: 0.5f, saturation: 1f, luminosity: 0.5f);

// Lighten / Darken / Mix
color.Lighten(.2);
color.Darken(.2);
color1.MixedWith(color2, fraction: 0.5);
Color.RandomHue();

Colormaps

IColormap colormap = new ScottPlot.Colormaps.Viridis();
Color[] colors = colormap.GetColors(20);

Dark Mode (verified)

var sig = formsPlot1.Plot.Add.Signal(Generate.SquareWaveFromSines());
sig.LineWidth = 3;
sig.Color = new Color("#2b9433");
sig.AlwaysUseLowDensityMode = true;

// Dark backgrounds
formsPlot1.Plot.FigureBackground.Color = new Color("#1c1c1e");
formsPlot1.Plot.DataBackground.Color = new Color("#2c2c2e");
formsPlot1.Plot.Axes.Color(new Color("#888888"));

// Grid fill + subtle lines
formsPlot1.Plot.Grid.XAxisStyle.FillColor1 = new Color("#888888").WithAlpha(10);
formsPlot1.Plot.Grid.YAxisStyle.FillColor1 = new Color("#888888").WithAlpha(10);
formsPlot1.Plot.Grid.XAxisStyle.MajorLineStyle.Color = Colors.White.WithAlpha(15);
formsPlot1.Plot.Grid.YAxisStyle.MajorLineStyle.Color = Colors.White.WithAlpha(15);
formsPlot1.Plot.Grid.XAxisStyle.MinorLineStyle.Color = Colors.White.WithAlpha(5);
formsPlot1.Plot.Grid.YAxisStyle.MinorLineStyle.Color = Colors.White.WithAlpha(5);
formsPlot1.Plot.Grid.XAxisStyle.MinorLineStyle.Width = 1;
formsPlot1.Plot.Grid.YAxisStyle.MinorLineStyle.Width = 1;

formsPlot1.Plot.Title("Dark Mode with Grid Fill");
formsPlot1.Plot.Axes.Title.Label.ForeColor = Colors.White;
formsPlot1.Refresh();

Color Mixing & Interpolation (verified)

// Color interpolation: Blue → Green
for (int i = 0; i <= 10; i++)
{
    double fraction = (double)i / 10;
    double x = i;
    double y = Math.Sin(Math.PI * 2 * fraction);
    var circle = formsPlot1.Plot.Add.Circle(x, y, 0.4);
    circle.FillColor = Colors.Blue.MixedWith(Colors.Green, fraction);
    circle.LineColor = Colors.Black.WithAlpha(128);
}
formsPlot1.Plot.Axes.SquareUnits();
formsPlot1.Plot.Title("Color Mixing: Blue → Green");
formsPlot1.Refresh();

Background Images

Image bgImage = new("background.png");
formsPlot1.Plot.DataBackground.Image = bgImage;
// or figure background:
formsPlot1.Plot.FigureBackground.Image = bgImage;
formsPlot1.Refresh();

Plottable Management

// Clear all plottables
formsPlot1.Plot.Clear();

// Remove specific plottable
formsPlot1.Plot.Remove(sig1);

// Remove all of a type
formsPlot1.Plot.Remove<ScottPlot.Plottables.Signal>();

// Move plottable to front
formsPlot1.Plot.MoveToTop(rect1);

Business Scenario Examples (Verified)

The following examples demonstrate real-world business chart patterns, all compiled and visually verified.

Stock Candlestick Chart with Volume

// Generate OHLC data
Random rand = new(42);
DateTime startDate = new DateTime(2025, 1, 2);
List<ScottPlot.OHLC> ohlcList = new();
double price = 150.0;
for (int i = 0; i < 60; i++)
{
    DateTime date = startDate.AddDays(i * 1.5);
    double open = price + rand.NextDouble() * 4 - 2;
    double close = open + rand.NextDouble() * 8 - 4;
    double high = Math.Max(open, close) + rand.NextDouble() * 3;
    double low = Math.Min(open, close) - rand.NextDouble() * 3;
    price = close;
    ohlcList.Add(new ScottPlot.OHLC(open, high, low, close, date, TimeSpan.FromDays(1)));
}

// Candlestick on left axis
var candle = formsPlot1.Plot.Add.Candlestick(ohlcList);
candle.Axes.YAxis = formsPlot1.Plot.Axes.Left;

// Volume bars on right axis with red/green coloring
var rightAxis = formsPlot1.Plot.Axes.Right;
ScottPlot.Bar[] volumeBars = new ScottPlot.Bar[ohlcList.Count];
for (int i = 0; i < ohlcList.Count; i++)
{
    double volume = rand.Next(500000, 3000000);
    bool isUp = ohlcList[i].Close >= ohlcList[i].Open;
    volumeBars[i] = new ScottPlot.Bar()
    {
        Position = ohlcList[i].DateTime.ToOADate(),
        Value = volume,
        Size = 0.6,
        FillColor = isUp
            ? new Color(38, 166, 91).WithAlpha(120)
            : new Color(220, 53, 69).WithAlpha(120),
    };
}
var barPlot = formsPlot1.Plot.Add.Bars(volumeBars);
barPlot.Axes.YAxis = rightAxis;

formsPlot1.Plot.Axes.DateTimeTicksBottom();
formsPlot1.Plot.Axes.Left.Label.Text = "Price (USD)";
formsPlot1.Plot.Axes.Right.Label.Text = "Volume";
formsPlot1.Plot.Title("AAPL Stock — Daily Candlestick + Volume");
formsPlot1.Plot.Axes.Right.Min = 0;
formsPlot1.Plot.Axes.Right.Max = 10000000;
formsPlot1.Refresh();

Sensor Temperature Monitoring (Dark Industrial Theme)

// Simulate 500 temperature readings (1 sample/sec)
Random rand = new(123);
double[] temperatures = new double[500];
double temp = 45.0;
for (int i = 0; i < temperatures.Length; i++)
{
    temp += rand.NextDouble() * 2 - 0.95;
    if (i > 300) temp += 0.15; // heat event
    temperatures[i] = Math.Round(temp, 1);
}

var sig = formsPlot1.Plot.Add.Signal(temperatures);
sig.Data.Period = 1.0;
sig.LineWidth = 2;
sig.Color = new Color("#00BFFF");
sig.LegendText = "Sensor T1";

// Warning threshold at 55°C
var warnLine = formsPlot1.Plot.Add.HorizontalLine(55);
warnLine.Color = Colors.Orange;
warnLine.LineWidth = 2;
warnLine.LinePattern = LinePattern.Dashed;
warnLine.LegendText = "Warning (55°C)";

// Critical threshold at 65°C
var critLine = formsPlot1.Plot.Add.HorizontalLine(65);
critLine.Color = Colors.Red;
critLine.LineWidth = 2;
critLine.LinePattern = LinePattern.Dashed;
critLine.LegendText = "Critical (65°C)";

// Danger zone
var dangerZone = formsPlot1.Plot.Add.HorizontalSpan(65, 80);
dangerZone.FillColor = Colors.Red.WithAlpha(25);
dangerZone.LegendText = "Danger Zone";

// Dark industrial theme
formsPlot1.Plot.FigureBackground.Color = new Color("#1a1a2e");
formsPlot1.Plot.DataBackground.Color = new Color("#16213e");
formsPlot1.Plot.Axes.Color(new Color("#a0a0a0"));
formsPlot1.Plot.Grid.MajorLineColor = Colors.White.WithAlpha(15);

formsPlot1.Plot.Title("Industrial Sensor — Temperature Monitor");
formsPlot1.Plot.Axes.Title.Label.ForeColor = Colors.White;
formsPlot1.Plot.XLabel("Time (seconds)");
formsPlot1.Plot.YLabel("Temperature (°C)");
formsPlot1.Plot.ShowLegend(Alignment.UpperLeft);
formsPlot1.Refresh();

Monthly Sales Year-over-Year Comparison

string[] months = { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
                    "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
double[] sales2024 = { 32, 28, 45, 38, 52, 48, 55, 61, 58, 63, 72, 85 };
double[] sales2025 = { 38, 35, 50, 42, 58, 55, 62, 70, 65, 71, 80, 95 };

Color color2024 = new Color("#5B9BD5");
Color color2025 = new Color("#ED7D31");
double barWidth = 0.35;

List<ScottPlot.Bar> bars = new();
for (int i = 0; i < 12; i++)
{
    bars.Add(new ScottPlot.Bar()
    {
        Position = i - barWidth / 2, Value = sales2024[i],
        Size = barWidth, FillColor = color2024,
    });
    bars.Add(new ScottPlot.Bar()
    {
        Position = i + barWidth / 2, Value = sales2025[i],
        Size = barWidth, FillColor = color2025,
    });
}
formsPlot1.Plot.Add.Bars(bars.ToArray());

// Month labels
Tick[] ticks = months.Select((m, i) => new Tick(i, m)).ToArray();
formsPlot1.Plot.Axes.Bottom.TickGenerator = new ScottPlot.TickGenerators.NumericManual(ticks);
formsPlot1.Plot.Axes.Margins(bottom: 0);

// Legend via invisible scatter
var leg1 = formsPlot1.Plot.Add.Scatter(new double[]{-100}, new double[]{-100});
leg1.Color = color2024; leg1.MarkerShape = MarkerShape.FilledSquare;
leg1.MarkerSize = 12; leg1.LineWidth = 0; leg1.LegendText = "2024";
var leg2 = formsPlot1.Plot.Add.Scatter(new double[]{-100}, new double[]{-100});
leg2.Color = color2025; leg2.MarkerShape = MarkerShape.FilledSquare;
leg2.MarkerSize = 12; leg2.LineWidth = 0; leg2.LegendText = "2025";

formsPlot1.Plot.Title("Monthly Sales Comparison — 2024 vs 2025");
formsPlot1.Plot.YLabel("Revenue (10K USD)");
formsPlot1.Plot.ShowLegend(Alignment.UpperLeft);
formsPlot1.Plot.Axes.SetLimitsX(-1, 12);
formsPlot1.Refresh();

Server CPU & Memory Dashboard (Dual Y Axes)

Random rand = new(99);
int points = 300;

// CPU: 20-90% with spikes
double[] cpu = new double[points];
double cpuBase = 35;
for (int i = 0; i < points; i++)
{
    cpuBase += rand.NextDouble() * 6 - 3;
    cpuBase = Math.Clamp(cpuBase, 15, 90);
    if (i > 100 && i < 140) cpuBase += 15;
    if (i > 200 && i < 220) cpuBase += 25;
    cpu[i] = Math.Round(cpuBase, 1);
}

// Memory: 4-12 GB with gradual increase (leak simulation)
double[] memory = new double[points];
double memBase = 5.5;
for (int i = 0; i < points; i++)
{
    memBase += rand.NextDouble() * 0.1 - 0.04;
    memBase = Math.Clamp(memBase, 4, 14);
    if (i > 150) memBase += 0.02;
    memory[i] = Math.Round(memBase, 2);
}

var cpuSig = formsPlot1.Plot.Add.Signal(cpu);
cpuSig.Data.Period = 1.0;
cpuSig.LineWidth = 2;
cpuSig.Color = new Color("#FF6B35");
cpuSig.LegendText = "CPU (%)";
cpuSig.Axes.YAxis = formsPlot1.Plot.Axes.Left;

var memSig = formsPlot1.Plot.Add.Signal(memory);
memSig.Data.Period = 1.0;
memSig.LineWidth = 2;
memSig.Color = new Color("#4ECDC4");
memSig.LegendText = "Memory (GB)";
memSig.Axes.YAxis = formsPlot1.Plot.Axes.Right;

// CPU danger threshold
var cpuThreshold = formsPlot1.Plot.Add.HorizontalLine(80);
cpuThreshold.Color = Colors.Red.WithAlpha(150);
cpuThreshold.LinePattern = LinePattern.Dotted;
cpuThreshold.Axes.YAxis = formsPlot1.Plot.Axes.Left;

formsPlot1.Plot.Axes.Left.Label.Text = "CPU Usage (%)";
formsPlot1.Plot.Axes.Left.Label.ForeColor = new Color("#FF6B35");
formsPlot1.Plot.Axes.Right.Label.Text = "Memory (GB)";
formsPlot1.Plot.Axes.Right.Label.ForeColor = new Color("#4ECDC4");

var ann = formsPlot1.Plot.Add.Annotation("CPU Spike @ 200s");
ann.Alignment = Alignment.UpperRight;

formsPlot1.Plot.Title("Server Performance Dashboard — Real-Time");
formsPlot1.Plot.XLabel("Time (seconds)");
formsPlot1.Plot.ShowLegend(Alignment.UpperLeft);
formsPlot1.Plot.Grid.MajorLineColor = Colors.Gray.WithOpacity(.15);
formsPlot1.Refresh();

Product Category Pie Chart with Custom Colors & Legend

double[] values = { 35, 25, 18, 12, 7, 3 };
var pie = formsPlot1.Plot.Add.Pie(values);
pie.ExplodeFraction = 0.05;

Color[] colors = {
    new Color("#4472C4"), new Color("#ED7D31"), new Color("#A5A5A5"),
    new Color("#FFC000"), new Color("#5B9BD5"), new Color("#70AD47"),
};
string[] labels = {
    "Electronics 35%", "Clothing 25%", "Food & Bev 18%",
    "Home 12%", "Sports 7%", "Other 3%",
};
for (int i = 0; i < pie.Slices.Count; i++)
{
    pie.Slices[i].FillColor = colors[i];
    pie.Slices[i].LegendText = labels[i];
}

formsPlot1.Plot.Title("Product Category Revenue Distribution — Q1 2025");
formsPlot1.Plot.Axes.Frameless();
formsPlot1.Plot.HideGrid();
formsPlot1.Plot.ShowLegend(Alignment.MiddleRight);
formsPlot1.Refresh();

Additional Resources

For complete API reference and advanced examples, see reference.md.