Axis and Ticks
Set Axis Limits
Axis Limits can be set by the user.
ScottPlot.Plot myPlot = new();
myPlot.Add.Signal(Generate.Sin(51));
myPlot.Add.Signal(Generate.Cos(51));
myPlot.Axes.SetLimits(-100, 150, -5, 5);
myPlot.SavePng("demo.png", 400, 300);
Read Axis Limits
Use GetLimits() to obtain the current axis limits.
ScottPlot.Plot myPlot = new();
myPlot.Add.Signal(Generate.Sin(51));
myPlot.Add.Signal(Generate.Cos(51));
AxisLimits limits = myPlot.Axes.GetLimits();
double xMin = limits.Left;
double xMax = limits.Right;
double yMin = limits.Bottom;
double yMax = limits.Top;
myPlot.SavePng("demo.png", 400, 300);
AutoScale Axis Limits to Fit Data
The axis limits can be automatically adjusted to fit the data. Optional arguments allow users to define the amount of whitespace around the edges of the data.In older versions of ScottPlot this functionality was achieved by a method named AxisAuto().
ScottPlot.Plot myPlot = new();
myPlot.Add.Signal(Generate.Sin(51));
myPlot.Add.Signal(Generate.Cos(51));
// set limits that do not fit the data
myPlot.Axes.SetLimits(-100, 150, -5, 5);
// reset limits to fit the data
myPlot.Axes.AutoScale();
myPlot.SavePng("demo.png", 400, 300);
Inverted Axis
Users can display data on an inverted axis by setting axis limits setting the lower edge to a value more positive than the upper edge.
ScottPlot.Plot myPlot = new();
myPlot.Add.Signal(Generate.Sin());
myPlot.Add.Signal(Generate.Cos());
myPlot.Axes.SetLimitsY(bottom: 1.5, top: -1.5);
myPlot.SavePng("demo.png", 400, 300);
Inverted Auto-Axis
Customize the logic for the automatic axis scaler to ensure that axis limits for a particular axis are always inverted when autoscaled.
ScottPlot.Plot myPlot = new();
myPlot.Add.Signal(Generate.Sin());
myPlot.Add.Signal(Generate.Cos());
myPlot.Axes.AutoScaler.InvertedY = true;
myPlot.SavePng("demo.png", 400, 300);
Square Axis Units
Axis rules can be put in place which force the vertical scale (units per pixel) to match the horizontal scale so circles always appear as circles and not stretched ellipses.
ScottPlot.Plot myPlot = new();
myPlot.Add.Circle(0, 0, 10);
// force pixels to have a 1:1 scale ratio
myPlot.Axes.SquareUnits();
// even if you try to "stretch" the axis, it will adjust the axis limits automatically
myPlot.Axes.SetLimits(-10, 10, -20, 20);
myPlot.SavePng("demo.png", 400, 300);
Axis with Subtitle
Users can create their own fully custom axes to replace the default ones (as demonstrated in the demo app). Some experimental axes are available for users who may be interested in alternative axis display styles.
ScottPlot.Plot myPlot = new();
// Plot some sample data
myPlot.Add.Signal(Generate.Sin());
myPlot.Add.Signal(Generate.Cos());
// Instantiate a custom axis and customize it as desired
ScottPlot.AxisPanels.Experimental.LeftAxisWithSubtitle customAxisY = new()
{
LabelText = "My Custom Y Axis",
SubLabelText = "It comes with a subtitle for the axis"
};
// Remove the default Y axis and add the custom one to the plot
myPlot.Axes.Remove(myPlot.Axes.Left);
myPlot.Axes.AddLeftAxis(customAxisY);
myPlot.SavePng("demo.png", 400, 300);
Axis AntiAliasing
To improve crispness of straight vertical and horizontal lines, Anti-aliasing is disabled by default for axis frames, tick marks, and grid lines. Anti-aliasing can be enabled for all these objects by calling the AntiAlias helper method.
ScottPlot.Plot myPlot = new();
double[] dataX = { 1, 2, 3, 4, 5 };
double[] dataY = { 1, 4, 9, 16, 25 };
myPlot.Add.Scatter(dataX, dataY);
myPlot.Axes.AntiAlias(true);
myPlot.SavePng("demo.png", 400, 300);
Hide Axis and Turn frame lines on/off
Demonstrates how to hide axis ticks and turn frame lines on and off.
ScottPlot.Plot myPlot = new();
myPlot.Add.Signal(Generate.Sin());
myPlot.Add.Signal(Generate.Cos());
// Hide axis label and tick
myPlot.Axes.Bottom.TickLabelStyle.IsVisible = false;
myPlot.Axes.Bottom.MajorTickStyle.Length = 0;
myPlot.Axes.Bottom.MinorTickStyle.Length = 0;
// Hide axis edge line
myPlot.Axes.Bottom.FrameLineStyle.Width = 0;
myPlot.Axes.Right.FrameLineStyle.Width = 0;
myPlot.Axes.Top.FrameLineStyle.Width = 0;
myPlot.SavePng("demo.png", 400, 300);
DateTime Axis Quickstart
Axis tick labels can be displayed using a time format.
ScottPlot.Plot myPlot = new();
// plot data using DateTime units
DateTime[] dates = Generate.ConsecutiveDays(100);
double[] ys = Generate.RandomWalk(100);
myPlot.Add.Scatter(dates, ys);
// tell the plot to display dates on the bottom axis
myPlot.Axes.DateTimeTicksBottom();
myPlot.SavePng("demo.png", 400, 300);
DateTime Axis Values
DateTime axes are achieved using Microsoft’s DateTime.ToOADate() and DateTime.FromOADate() methods to convert between dates and numeric values. Advanced users who wish to display data on DateTime axes may prefer to work with collections of doubles rather than collections of DateTimes.
ScottPlot.Plot myPlot = new();
// create an array of DateTimes one hour apart
int numberOfHours = 24;
DateTime[] dateTimes = new DateTime[numberOfHours];
DateTime startDateTime = new(2024, 1, 1);
TimeSpan deltaTimeSpan = TimeSpan.FromHours(1);
for (int i = 0; i < numberOfHours; i++)
{
dateTimes[i] = startDateTime + i * deltaTimeSpan;
}
// create an array of doubles representing the same DateTimes one hour apart
double[] dateDoubles = new double[numberOfHours];
double startDouble = startDateTime.ToOADate(); // days since 1900
double deltaDouble = 1.0 / 24.0; // an hour is 1/24 of a day
for (int i = 0; i < numberOfHours; i++)
{
dateDoubles[i] = startDouble + i * deltaDouble;
}
// now both arrays represent the same dates
myPlot.Add.Scatter(dateTimes, Generate.Sin(numberOfHours));
myPlot.Add.Scatter(dateDoubles, Generate.Cos(numberOfHours));
myPlot.Axes.DateTimeTicksBottom();
// add padding on the right to make room for wide tick labels
myPlot.Axes.Right.MinimumSize = 50;
myPlot.SavePng("demo.png", 400, 300);
Custom DateTime Label Format
Users can provide their own logic for customizing DateTime tick labels
ScottPlot.Plot myPlot = new();
// plot sample DateTime data
DateTime[] dates = Generate.ConsecutiveDays(100);
double[] ys = Generate.RandomWalk(100);
myPlot.Add.Scatter(dates, ys);
myPlot.Axes.DateTimeTicksBottom();
// add logic into the RenderStarting event to customize tick labels
myPlot.RenderManager.RenderStarting += (s, e) =>
{
Tick[] ticks = myPlot.Axes.Bottom.TickGenerator.Ticks;
for (int i = 0; i < ticks.Length; i++)
{
DateTime dt = DateTime.FromOADate(ticks[i].Position);
string label = $"{dt:MMM} '{dt:yy}";
ticks[i] = new Tick(ticks[i].Position, label);
}
};
myPlot.SavePng("demo.png", 400, 300);
DateTime Axis Fixed Interval Ticks
Make ticks render at fixed intervals. Optionally make the ticks render from a custom start date, rather than using the start date of the plot (e.g. to draw ticks on the hour every hour, or on the first of every month, etc).
ScottPlot.Plot myPlot = new();
// Plot 24 hours sample DateTime data (1 point every minute)
DateTime[] dates = Generate.ConsecutiveMinutes(24 * 60, new DateTime(2000, 1, 1, 2, 12, 0));
double[] ys = Generate.RandomWalk(24 * 60);
myPlot.Add.Scatter(dates, ys);
var dtAx = myPlot.Axes.DateTimeTicksBottom();
// Create fixed-intervals ticks, major ticks every 6 hours, minor ticks every hour
dtAx.TickGenerator = new ScottPlot.TickGenerators.DateTimeFixedInterval(
new ScottPlot.TickGenerators.TimeUnits.Hour(), 6,
new ScottPlot.TickGenerators.TimeUnits.Hour(), 1,
// Here we provide a delegate to override when the ticks start. In this case, we want the majors to be
// 00:00, 06:00, 12:00, etc. and the minors to be on the hour, every hour, so we start at midnight.
// If you do not provide this delegate, the ticks will start at whatever the Min on the x-axis is.
// The major ticks might end up as 1:30am, 7:30am, etc, and the tick positions will be fixed on the plot
// when it is panned around.
dt => new DateTime(dt.Year, dt.Month, dt.Day));
// Customise gridlines to make the ticks easier to see
myPlot.Grid.XAxisStyle.MajorLineStyle.Color = Colors.Black.WithOpacity();
myPlot.Grid.XAxisStyle.MajorLineStyle.Width = 2;
myPlot.Grid.XAxisStyle.MinorLineStyle.Color = Colors.Gray.WithOpacity(0.25);
myPlot.Grid.XAxisStyle.MinorLineStyle.Width = 1;
myPlot.Grid.XAxisStyle.MinorLineStyle.Pattern = LinePattern.DenselyDashed;
// Remove labels on minor ticks, otherwise there is a lot of tick label overlap
myPlot.RenderManager.RenderStarting += (s, e) =>
{
Tick[] ticks = myPlot.Axes.Bottom.TickGenerator.Ticks;
for (int i = 0; i < ticks.Length; i++)
{
if (ticks[i].IsMajor)
{
continue;
}
ticks[i] = new Tick(ticks[i].Position, "", ticks[i].IsMajor);
}
};
myPlot.SavePng("demo.png", 400, 300);
Floating Axis
A floating or centered axis may be realized by hiding the default axes which appear at the edges of the plot and creating a new floating axis and adding it to the plot.
ScottPlot.Plot myPlot = new();
// create floating X and Y axes using one of the existing axes for reference
ScottPlot.Plottables.FloatingAxis floatingX = new(myPlot.Axes.Bottom);
ScottPlot.Plottables.FloatingAxis floatingY = new(myPlot.Axes.Left);
// hide the default axes and add the custom ones to the plot
myPlot.Axes.Frameless();
myPlot.HideGrid();
myPlot.Add.Plottable(floatingX);
myPlot.Add.Plottable(floatingY);
// add sample data last so it appears on top
myPlot.Add.Signal(Generate.Sin(51));
myPlot.Add.Signal(Generate.Cos(51));
myPlot.SavePng("demo.png", 400, 300);
Grid Line Style
Grid lines have many options to allow extensive customization.
ScottPlot.Plot myPlot = new();
myPlot.Add.Signal(Generate.Sin(51));
myPlot.Add.Signal(Generate.Cos(51));
myPlot.Grid.LineColor = Colors.Blue.WithAlpha(.2);
myPlot.Grid.LinePattern = LinePattern.Dotted;
myPlot.SavePng("demo.png", 400, 300);
Image Axis Label
For cases where axis label font styling does not provide the desired level of customization, a bitmap image may be displayed as an axis label. This strategy allows rich text to be realized using any third party tool that can render that text as a bitmap. It also enables users to place icons or images in their axis labels.
ScottPlot.Plot myPlot = new();
myPlot.Add.Signal(Generate.Sin(51));
myPlot.Add.Signal(Generate.Cos(51));
// This array holds the bytes of a bitmap. Here it's generated,
// but it could be a byte array read from a bitmap file on disk.
byte[] bytes1 = SampleImages.NoisyText("Horiz", 150, 50).GetImageBytes();
byte[] bytes2 = SampleImages.NoisyText("Vert", 150, 50).GetImageBytes();
// Create a ScottPlot.Image from the bitmap bytes
ScottPlot.Image img1 = new(bytes1);
ScottPlot.Image img2 = new(bytes2);
// Display the image for the bottom axis label
myPlot.Axes.Bottom.Label.Image = img1;
myPlot.Axes.Left.Label.Image = img2;
myPlot.SavePng("demo.png", 400, 300);
Multiplier Notation
Numeric tick labels may be displayed using multiplier notation (where tick labels are displayed using scientific notation with the eponent displayed in the corner of the plot). A helper method is available to set-up multiplier notation with a single statement, but users can interact with the object this method returns (not shown here) or inspect the code inside of that method to learn how to achieve enhanced customization abilities.
ScottPlot.Plot myPlot = new();
// plot sample data with extremely large values
double[] xs = Generate.RandomSample(50, -1e10, 1e10);
double[] ys = Generate.RandomSample(50, -1e20, 1e20);
myPlot.Add.Scatter(xs, ys);
// enable multiplier notation on both primary axes
myPlot.Axes.SetupMultiplierNotation(myPlot.Axes.Left);
myPlot.Axes.SetupMultiplierNotation(myPlot.Axes.Bottom);
myPlot.SavePng("demo.png", 400, 300);