Customizing Ticks
Custom Tick Formatters
Users can customize the logic used to create tick labels from tick positions. Old versions of ScottPlot achieved this using a ManualTickPositions method.
ScottPlot.Plot myPlot = new();
double[] xs = Generate.Consecutive(100, 1, -50);
myPlot.Add.Scatter(xs, Generate.Sin(100));
myPlot.Add.Scatter(xs, Generate.Cos(100));
// create a static function containing the string formatting logic
static string CustomFormatter(double position)
{
if (position == 0)
return "0";
else if (position > 0)
return $"+{position}";
else
return $"({-position})";
}
// create a custom tick generator using your custom label formatter
ScottPlot.TickGenerators.NumericAutomatic myTickGenerator = new()
{
LabelFormatter = CustomFormatter
};
// tell an axis to use the custom tick generator
myPlot.Axes.Bottom.TickGenerator = myTickGenerator;
myPlot.SavePng("demo.png", 400, 300);
DateTimeAutomatic Tick Formatters
Users can customize the logic used to create datetime tick labels from tick positions.
ScottPlot.Plot myPlot = new();
// plot data using DateTime values on the horizontal axis
DateTime[] xs = Generate.ConsecutiveHours(100);
double[] ys = Generate.RandomWalk(100);
myPlot.Add.Scatter(xs, ys);
// setup the bottom axis to use DateTime ticks
var axis = myPlot.Axes.DateTimeTicksBottom();
// create a custom formatter to return a string with
// date only when zoomed out and time only when zoomed in
static string CustomFormatter(DateTime dt)
{
bool isMidnight = dt is { Hour: 0, Minute: 0, Second: 0 };
return isMidnight
? DateOnly.FromDateTime(dt).ToString()
: TimeOnly.FromDateTime(dt).ToString();
}
// apply our custom tick formatter
var tickGen = (ScottPlot.TickGenerators.DateTimeAutomatic)axis.TickGenerator;
tickGen.LabelFormatter = CustomFormatter;
myPlot.SavePng("demo.png", 400, 300);
Custom Tick Generators
Tick generators determine where ticks are to be placed and also contain logic for generating tick labels from tick positions. Alternative tick generators can be created and assigned to axes. Some common tick generators are provided with ScottPlot, and users also have the option create their own.
ScottPlot.Plot myPlot = new();
myPlot.Add.Signal(Generate.Sin(51));
myPlot.Add.Signal(Generate.Cos(51));
myPlot.Axes.Bottom.TickGenerator = new ScottPlot.TickGenerators.NumericFixedInterval(11);
myPlot.SavePng("demo.png", 400, 300);
SetTicks Shortcut
The default axes have a SetTicks() helper method which replaces the default tick generator with a manual tick generator pre-loaded with the provided ticks.
ScottPlot.Plot myPlot = new();
// display sample data
myPlot.Add.Signal(Generate.Sin());
myPlot.Add.Signal(Generate.Cos());
// use manually defined ticks
double[] tickPositions = { 10, 25, 40 };
string[] tickLabels = { "Alpha", "Beta", "Gamma" };
myPlot.Axes.Bottom.SetTicks(tickPositions, tickLabels);
myPlot.SavePng("demo.png", 400, 300);
Custom Tick Positions
Users desiring more control over major and minor tick positions and labels can instantiate a manual tick generator, set it up as desired, then assign it to the axis being customized
ScottPlot.Plot myPlot = new();
// display sample data
myPlot.Add.Signal(Generate.Sin());
myPlot.Add.Signal(Generate.Cos());
// create a manual tick generator and add ticks
ScottPlot.TickGenerators.NumericManual ticks = new();
// add major ticks with their labels
ticks.AddMajor(0, "zero");
ticks.AddMajor(20, "twenty");
ticks.AddMajor(50, "fifty");
// add minor ticks
ticks.AddMinor(22);
ticks.AddMinor(25);
ticks.AddMinor(32);
ticks.AddMinor(35);
ticks.AddMinor(42);
ticks.AddMinor(45);
// tell the horizontal axis to use the custom tick generator
myPlot.Axes.Bottom.TickGenerator = ticks;
myPlot.SavePng("demo.png", 400, 300);
Custom Tick DateTimes
Users may define custom ticks using DateTime units
ScottPlot.Plot myPlot = new();
DateTime[] dates = Generate.ConsecutiveDays(100);
double[] values = Generate.RandomWalk(100);
myPlot.Add.Scatter(dates, values);
// create a manual DateTime tick generator and add ticks
ScottPlot.TickGenerators.DateTimeManual ticks = new();
// add ticks for Mondays only
foreach (DateTime date in dates)
{
if (date.DayOfWeek == DayOfWeek.Monday)
{
string label = date.DayOfYear.ToString();
ticks.AddMajor(date, label);
}
}
// tell the horizontal axis to use the custom tick generator
myPlot.Axes.Bottom.TickGenerator = ticks;
// style the plot
myPlot.Title("Monday Ticks");
myPlot.XLabel("Day of the Year");
myPlot.SavePng("demo.png", 400, 300);
Rotated Tick Labels
Users can customize tick label rotation.
ScottPlot.Plot myPlot = new();
myPlot.Add.Signal(Generate.Sin());
myPlot.Add.Signal(Generate.Cos());
myPlot.Axes.Bottom.TickLabelStyle.Rotation = -45;
myPlot.Axes.Bottom.TickLabelStyle.Alignment = Alignment.MiddleRight;
myPlot.SavePng("demo.png", 400, 300);
Rotated Tick with Long Labels
The axis size can be increased to accommodate rotated or long tick labels.
ScottPlot.Plot myPlot = new();
// create a bar plot
double[] values = { 5, 10, 7, 13, 25, 60 };
myPlot.Add.Bars(values);
myPlot.Axes.Margins(bottom: 0);
// create a tick for each bar
Tick[] ticks =
{
new(0, "First Long Title"),
new(1, "Second Long Title"),
new(2, "Third Long Title"),
new(3, "Fourth Long Title"),
new(4, "Fifth Long Title"),
new(5, "Sixth Long Title")
};
myPlot.Axes.Bottom.TickGenerator = new ScottPlot.TickGenerators.NumericManual(ticks);
myPlot.Axes.Bottom.TickLabelStyle.Rotation = 45;
myPlot.Axes.Bottom.TickLabelStyle.Alignment = Alignment.MiddleLeft;
// determine the width of the largest tick label
float largestLabelWidth = 0;
using Paint paint = Paint.NewDisposablePaint();
foreach (Tick tick in ticks)
{
PixelSize size = myPlot.Axes.Bottom.TickLabelStyle.Measure(tick.Label, paint).Size;
largestLabelWidth = Math.Max(largestLabelWidth, size.Width);
}
// ensure axis panels do not get smaller than the largest label
myPlot.Axes.Bottom.MinimumSize = largestLabelWidth;
myPlot.Axes.Right.MinimumSize = largestLabelWidth;
myPlot.SavePng("demo.png", 400, 300);
Disable Grid Lines
Users can disable grid lines for specific axes.
ScottPlot.Plot myPlot = new();
myPlot.Add.Signal(Generate.Sin());
myPlot.Add.Signal(Generate.Cos());
myPlot.Grid.XAxisStyle.IsVisible = true;
myPlot.Grid.YAxisStyle.IsVisible = false;
myPlot.SavePng("demo.png", 400, 300);
Minimum Tick Spacing
Space between ticks can be increased by setting a value to indicate the minimum distance between tick labels (in pixels).
ScottPlot.Plot myPlot = new();
myPlot.Add.Signal(Generate.Sin(51));
myPlot.Add.Signal(Generate.Cos(51));
ScottPlot.TickGenerators.NumericAutomatic tickGenX = new();
tickGenX.MinimumTickSpacing = 50;
myPlot.Axes.Bottom.TickGenerator = tickGenX;
ScottPlot.TickGenerators.NumericAutomatic tickGenY = new();
tickGenY.MinimumTickSpacing = 25;
myPlot.Axes.Left.TickGenerator = tickGenY;
myPlot.SavePng("demo.png", 400, 300);
Tick Density
Tick density can be adjusted as a fraction of the default value. Unlike MinimumTickSpacing, this strategy is aware of the size of tick labels and adjusts accordingly.
ScottPlot.Plot myPlot = new();
myPlot.Add.Signal(Generate.Sin(51));
myPlot.Add.Signal(Generate.Cos(51));
ScottPlot.TickGenerators.NumericAutomatic tickGenX = new();
tickGenX.TickDensity = 0.2;
myPlot.Axes.Bottom.TickGenerator = tickGenX;
ScottPlot.TickGenerators.NumericAutomatic tickGenY = new();
tickGenY.TickDensity = 0.2;
myPlot.Axes.Left.TickGenerator = tickGenY;
myPlot.SavePng("demo.png", 400, 300);
Tick Count
A target number of ticks can be provided and the automatic tick generator will attempt to place that number of ticks. This strategy allows tick density to decrease as the image size increases.
ScottPlot.Plot myPlot = new();
myPlot.Add.Signal(Generate.Sin(51));
myPlot.Add.Signal(Generate.Cos(51));
ScottPlot.TickGenerators.NumericAutomatic tickGenX = new();
tickGenX.TargetTickCount = 3;
myPlot.Axes.Bottom.TickGenerator = tickGenX;
ScottPlot.TickGenerators.NumericAutomatic tickGenY = new();
tickGenY.TargetTickCount = 3;
myPlot.Axes.Left.TickGenerator = tickGenY;
myPlot.SavePng("demo.png", 400, 300);
Minor Tick Density
Minor tick marks are automatically generated at intervals between major tick marks. By default they are evenly spaced, but their density may be customized.
ScottPlot.Plot myPlot = new();
// plot sample data
double[] xs = Generate.Consecutive(100);
double[] ys = Generate.NoisyExponential(100);
var sp = myPlot.Add.Scatter(xs, ys);
sp.LineWidth = 0;
// create a minor tick generator with 10 minor ticks per major tick
ScottPlot.TickGenerators.EvenlySpacedMinorTickGenerator minorTickGen = new(10);
// create a numeric tick generator that uses our custom minor tick generator
ScottPlot.TickGenerators.NumericAutomatic tickGen = new();
tickGen.MinorTickGenerator = minorTickGen;
// tell the left axis to use our custom tick generator
myPlot.Axes.Left.TickGenerator = tickGen;
myPlot.SavePng("demo.png", 400, 300);
Log Scale Tick Marks
The appearance of logarithmic scaling can be achieved by log-scaling the data to be displayed then customizing the minor ticks and grid.
ScottPlot.Plot myPlot = new();
// start with original data
double[] xs = Generate.Consecutive(100);
double[] ys = Generate.NoisyExponential(100);
// log-scale the data and account for negative values
double[] logYs = ys.Select(Math.Log10).ToArray();
// add log-scaled data to the plot
myPlot.Add.ScatterPoints(xs, logYs);
// create a minor tick generator that places log-distributed minor ticks
ScottPlot.TickGenerators.LogMinorTickGenerator minorTickGen = new();
// create a numeric tick generator that uses our custom minor tick generator
ScottPlot.TickGenerators.NumericAutomatic tickGen = new();
tickGen.MinorTickGenerator = minorTickGen;
// create a custom tick formatter to set the label text for each tick
static string LogTickLabelFormatter(double y) => $"{Math.Pow(10, y):N0}";
// tell our major tick generator to only show major ticks that are whole integers
tickGen.IntegerTicksOnly = true;
// tell our custom tick generator to use our new label formatter
tickGen.LabelFormatter = LogTickLabelFormatter;
// tell the left axis to use our custom tick generator
myPlot.Axes.Left.TickGenerator = tickGen;
// show grid lines for minor ticks
myPlot.Grid.MajorLineColor = Colors.Black.WithOpacity(.15);
myPlot.Grid.MinorLineColor = Colors.Black.WithOpacity(.05);
myPlot.Grid.MinorLineWidth = 1;
myPlot.SavePng("demo.png", 400, 300);
Log Scale with Custom Tick Marks
Placement of minor tick marks in plots with logarithmic axes may my customized using a custom minor tick generator. Some may be bundled with ScottPlot as shown here, but users may create their own and apply them as seen here.
ScottPlot.Plot myPlot = new();
double[] xs = Generate.Consecutive(100);
double[] logYs = Generate.NoisyExponential(100).Select(Math.Log10).ToArray();
var sp = myPlot.Add.ScatterPoints(xs, logYs);
// this tick generator places 10 ticks (decimal distribution) between major log ticks
IMinorTickGenerator minorTickGen = new ScottPlot.TickGenerators.LogDecadeMinorTickGenerator();
// create a numeric tick generator that uses our custom minor tick generator
ScottPlot.TickGenerators.NumericAutomatic tickGen = new()
{
MinorTickGenerator = minorTickGen,
IntegerTicksOnly = true,
LabelFormatter = (double y) => $"{Math.Pow(10, y):N0}",
};
// tell the left axis to use our custom tick generator and configure the grid to show ticks
myPlot.Axes.Left.TickGenerator = tickGen;
myPlot.Grid.MajorLineColor = Colors.Black.WithOpacity(.15);
myPlot.Grid.MinorLineColor = Colors.Black.WithOpacity(.05);
myPlot.Grid.MinorLineWidth = 1;
myPlot.SavePng("demo.png", 400, 300);