Advanced Axis Features - ScottPlot 4.1 Cookbook

This page contains recipes for the Advanced Axis Features category.
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Generated by ScottPlot 4.1.61 on 2/27/2023

Advanced Grid Customization

Grid lines can be extensively customized using various configuration methods.

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

// plot sample data
plt.AddSignal(DataGen.Sin(51));
plt.AddSignal(DataGen.Cos(51));

// advanced grid customizations are available by accessing Axes directly
plt.XAxis.MajorGrid(color: Color.FromArgb(100, Color.Black));
plt.XAxis.MinorGrid(enable: true, color: Color.FromArgb(20, Color.Black));
plt.YAxis.MajorGrid(lineWidth: 2, lineStyle: LineStyle.Dash, color: Color.Magenta);

plt.SaveFig("asis_gridAdvanced.png");

Numeric Format String

Tick labels can be converted to text using a custom format string.

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

// plot sample data
plt.AddSignal(DataGen.Sin(51));
plt.AddSignal(DataGen.Cos(51));

// See https://tinyurl.com/y86clj9k to learn about numeric format strings
plt.XAxis.TickLabelFormat("E2", dateTimeFormat: false);
plt.YAxis.TickLabelFormat("P1", dateTimeFormat: false);

plt.SaveFig("ticks_numericFormatString.png");

Manual Tick Labels

Tick positions and labels can be defined manually.

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

// plot sample data
plt.AddSignal(DataGen.Sin(51));
plt.AddSignal(DataGen.Cos(51));

// manually define X axis tick positions and labels
double[] xPositions = { 7, 21, 37, 46 };
string[] xLabels = { "VII", "XXI", "XXXVII", "XLVI" };
plt.XAxis.ManualTickPositions(xPositions, xLabels);

// manually define Y axis tick positions and labels
double[] yPositions = { -1, 0, .5, 1 };
string[] yLabels = { "bottom", "center", "half", "top" };
plt.YAxis.ManualTickPositions(yPositions, yLabels);

plt.SaveFig("ticks_defined.png");

Manual and Automatic Tick Labels

Tick positions and labels can be defined manually, but also added alongside automatic tick labels.

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

plt.AddSignal(DataGen.Sin(15), 2);
plt.AddSignal(DataGen.Cos(15), 2);

double[] positions = { Math.PI, 2 * Math.PI };
string[] labels = { "π", "2π" };
plt.XAxis.AutomaticTickPositions(positions, labels);
plt.XAxis.TickDensity(0.5);

plt.SaveFig("ticks_defined_and_unioned.png");

NonLinear Tick Spacing

Plot data on regular cartesian space then manually control axis labels to give the appearance of non-linear spacing between points.

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

// these are our nonlinear data values we wish to plot
double[] amplitudes = { 23.9, 24.2, 24.3, 24.5, 25.3, 26.3, 27.6, 31.4, 33.7, 36,
38.4, 42, 43.5, 46.1, 48.8, 51.5, 53.2, 55, 56.9, 58.7, 60.6 };
double[] frequencies = { 50, 63, 80, 100, 125, 160, 200, 250, 315, 400, 500, 630,
 800, 1000, 1250, 1600, 2000, 2500, 3150, 4000, 5000 };

// ignore the "real" X values and plot data at consecutive X values (0, 1, 2, 3...)
double[] positions = DataGen.Consecutive(frequencies.Length);
plt.AddScatter(positions, amplitudes);

// then define tick labels based on "real" X values, rotate them, and give them extra space
string[] labels = frequencies.Select(x => x.ToString()).ToArray();
plt.XAxis.ManualTickPositions(positions, labels);
plt.XAxis.TickLabelStyle(rotation: 45);
plt.XAxis.SetSizeLimit(min: 50); // extra space for rotated ticks

// apply axis labels, trigging a layout reset
plt.Title("Vibrational Coupling");
plt.YLabel("Amplitude (dB)");
plt.XLabel("Frequency (Hz)");

plt.SaveFig("ticks_nonLinearX.png");

ScottPlot will always display data where X values ascend from left to right. To simulate an inverted axis (where numbers decrease from left to right) plot data in the negative space, then invert the sign of tick labels.

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

// plot the positive data in the negative space
double[] values = DataGen.Sin(50);
var sig = plt.AddSignal(values);
sig.OffsetX = -50;

// then invert the sign of the axis tick labels
plt.XAxis.TickLabelNotation(invertSign: true);
plt.YAxis.TickLabelNotation(invertSign: true);

plt.SaveFig("ticks_descending.png");

Defined Tick Spacing

The space between tick marks can be manually defined by setting the grid spacing.

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

// plot the positive data in the negative space
double[] values = DataGen.Sin(50);
var sig = plt.AddSignal(values);
sig.OffsetX = -50;

// then invert the sign of the axis tick labels
plt.XAxis.ManualTickSpacing(2);
plt.YAxis.ManualTickSpacing(.1);

plt.SaveFig("ticks_definedSpacing.png");

Tick Label Culture

Large numbers and dates are formatted differently for different cultures. Hungarian uses spaces to separate large numbers and periods to separate fields in dates.

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

// generate some data
double[] price = DataGen.RandomWalk(null, 60 * 8, 10000);
DateTime start = new DateTime(2019, 08, 25, 8, 30, 00);
double pointsPerDay = 24 * 60;

// create the plot
var sig = plt.AddSignal(price, pointsPerDay);
sig.OffsetX = start.ToOADate();

// set the localization
var culture = System.Globalization.CultureInfo.CreateSpecificCulture("hu"); // Hungarian
plt.SetCulture(culture);

// further decorate the plot
plt.XAxis.DateTimeFormat(true);
plt.YAxis.Label("Price");
plt.XAxis.Label("Date and Time");
plt.XAxis2.Label("Hungarian Formatted DateTime Tick Labels");

plt.SaveFig("ticks_culture.png");

Custom Tick Label Culture

SetCulture() as arguments to let the user manually define formatting strings which will be used globally to change how numbers and dates are formatted.

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

// generate 10 days of data
int pointCount = 10;
double[] values = DataGen.RandomWalk(null, pointCount);
double[] days = new double[pointCount];
DateTime day1 = new DateTime(1985, 09, 24);
for (int i = 0; i < days.Length; i++)
    days[i] = day1.AddDays(1).AddDays(i).ToOADate();

// plot the data with custom tick format (https://tinyurl.com/ycwh45af)
plt.AddScatter(days, values);
plt.XAxis.TickLabelFormat("M\\/dd", dateTimeFormat: true);

plt.SaveFig("ticks_cultureCustom.png");

Multiplier Notation

Multiplier notation keeps tick labels small when plotting large data values. This style is also called engineering notation or scientific notation.

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

plt.AddLine(-1e5, -1e10, 1e5, 1e10);

plt.XAxis.TickLabelNotation(multiplier: true);
plt.YAxis.TickLabelNotation(multiplier: true);

plt.SaveFig("ticks_multiplier.png");

Offset Notation

Offset notation keeps tick labels small when plotting large data values that are close together.

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

plt.AddLine(1e5 + 111, 1e10 + 111, 1e5 + 222, 1e10 + 222);

plt.XAxis.TickLabelNotation(offset: true);
plt.YAxis.TickLabelNotation(offset: true);

plt.SaveFig("ticks_offset.png");

Defined DateTime Spacing

This example shows how to use a fixed inter-tick distance for a DateTime axis

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

// create a series of dates
int pointCount = 20;
double[] dates = new double[pointCount];
var firstDay = new DateTime(2020, 1, 22);
for (int i = 0; i < pointCount; i++)
    dates[i] = firstDay.AddDays(i).ToOADate();

// simulate data for each date
double[] values = new double[pointCount];
Random rand = new Random(0);
for (int i = 1; i < pointCount; i++)
    values[i] = values[i - 1] + rand.NextDouble();

plt.AddScatter(dates, values);
plt.XAxis.DateTimeFormat(true);

// define tick spacing as 1 day (every day will be shown)
plt.XAxis.ManualTickSpacing(1, ScottPlot.Ticks.DateTimeUnit.Day);
plt.XAxis.TickLabelStyle(rotation: 45);

// add some extra space for rotated ticks
plt.XAxis.SetSizeLimit(min: 50);

plt.SaveFig("ticks_definedDateTimeSpace.png");

Log Scale

ScottPlot is designed to display 2D data on linear X and Y axes, but you can log-transform data before plotting it and customize the ticks and grid to give the appearance of logarithmic scales.

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

// These are the dat we will plot with a linear X scale but log Y scale
double[] xs = { 1, 2, 3, 4, 5 };
double[] ys = { 10, 2_000, 50_000, 1_000_000, 1_500_000 };

// Plot the Log10 of all the Y values
double[] logYs = ys.Select(y => Math.Log10(y)).ToArray();
var scatter = plt.AddScatter(xs, logYs, lineWidth: 2, markerSize: 10);

// Use a custom formatter to control the label for each tick mark
static string logTickLabels(double y) => Math.Pow(10, y).ToString("N0");
plt.YAxis.TickLabelFormat(logTickLabels);

// Use log-spaced minor tick marks and grid lines to make it more convincing
plt.YAxis.MinorLogScale(true);
plt.YAxis.MajorGrid(true, Color.FromArgb(80, Color.Black));
plt.YAxis.MinorGrid(true, Color.FromArgb(20, Color.Black));
plt.XAxis.MajorGrid(true, Color.FromArgb(80, Color.Black));

// Set the axis limits manually to ensure edges terminate at desirable locations
plt.SetAxisLimits(0, 6, 0, Math.Log10(10_000_000));

plt.SaveFig("asis_log.png");

Log Scale Tick Density

Numer of minor ticks between major ticks can be customized.

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

double[] ys = ScottPlot.DataGen.Range(100, 10_000, 100, true);
double[] xs = ScottPlot.DataGen.Consecutive(ys.Length);
double[] logYs = ys.Select(y => Math.Log10(y)).ToArray();

var scatter = plt.AddScatter(xs, logYs);

static string logTickLabels(double y) => Math.Pow(10, y).ToString("N0");
plt.YAxis.TickLabelFormat(logTickLabels);

// set the number of minor ticks per major tick here
plt.YAxis.MinorLogScale(true, minorTickCount: 20);

// darken grid line colors
plt.YAxis.MinorGrid(true);
plt.YAxis.MinorGrid(true, Color.FromArgb(20, Color.Black));
plt.YAxis.MajorGrid(true, Color.FromArgb(80, Color.Black));
plt.XAxis.MajorGrid(true, Color.FromArgb(80, Color.Black));

plt.SaveFig("asis_logTickDensity.png");

Ruler mode

Ruler mode is an alternative way to display axis ticks. It draws long ticks and offsets the tick labels to give the appearance of a ruler.

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

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

plt.XAxis.RulerMode(true);
plt.YAxis.RulerMode(true);

plt.SaveFig("asis_ruler.png");

Polar Coordinates

A helper function converts radius and theta arrays into Cartesian coordinates suitable for plotting with traditioanl plot types.

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

// create data with polar coordinates
int count = 400;
double step = 0.01;

double[] rs = new double[count];
double[] thetas = new double[count];

for (int i = 0; i < rs.Length; i++)
{
    rs[i] = 1 + i * step;
    thetas[i] = i * 2 * Math.PI * step;
}

// convert polar data to Cartesian data
(double[] xs, double[] ys) = ScottPlot.Tools.ConvertPolarCoordinates(rs, thetas);

// plot the Cartesian data
plt.AddScatter(xs, ys);

// decorate the plot
plt.Title("Scatter Plot of Polar Data");
plt.AxisScaleLock(true);

plt.SaveFig("asis_polar.png");

Images as Axis Labels

Images can be used as axis labels to allow for things like LaTeX axis labels.

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

// create an interesting plot
double[] xs = DataGen.Range(-5, 5, .5);
double[] ys = DataGen.Range(-5, 5, .5);
Vector2[,] vectors = new Vector2[xs.Length, ys.Length];
for (int i = 0; i < xs.Length; i++)
    for (int j = 0; j < ys.Length; j++)
        vectors[i, j] = new Vector2(ys[j], -15 * Math.Sin(xs[i]));
plt.AddVectorField(vectors, xs, ys, colormap: Drawing.Colormap.Turbo);

// use images as axis labels
plt.XAxis.ImageLabel(new Bitmap("Images/theta.png"));
plt.YAxis.ImageLabel(new Bitmap("Images/d_theta_dt.png"));

plt.SaveFig("asis_image.png");

Transparent Images Axis Labels

Transparency in PNGs is respected, but JPEG files do not support transparency.

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

plt.Style(Style.Light2);
plt.AddSignal(DataGen.Sin(51));
plt.AddSignal(DataGen.Cos(51));

// vertical axis label uses a transparent PNG
plt.YAxis.ImageLabel(new Bitmap("Images/d_theta_dt.png"));

// horizontal axis label uses a non-transparent JPEG
plt.XAxis.ImageLabel(new Bitmap("Images/theta.jpg"));

plt.SaveFig("asis_imageTransparent.png");

Tick Density

Axis tick density can be adjusted by the user. The largest the density is, the more ticks are displayed. Setting this value too high will result in overlapping tick labels.

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

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

plt.XAxis.Label("Lower Density Ticks");
plt.XAxis.TickDensity(0.2);

plt.YAxis.Label("Higher Density Ticks");
plt.YAxis.TickDensity(3);

plt.SaveFig("asis_tickDensity.png");

Minimum Tick Spacing

Minimum tick spacing can be defined such that zooming in does not produce more grid lines, ticks, and tick labels beyond the defined limit.

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

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

plt.YAxis.MinimumTickSpacing(1);
plt.XAxis.MinimumTickSpacing(25);

plt.SaveFig("asis_minimumTickSpacing.png");

Custom Tick Formatter

For ultimate control over tick label format you can create a custom formatter function and use that to convert positions to labels. This allows logic to be used to format tick labels.

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

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

// create a custom formatter as a static class
static string customTickFormatter(double position)
{
    if (position == 0)
        return "zero";
    else if (position > 0)
        return $"+{position:F2}";
    else
        return $"({Math.Abs(position):F2})";
}

// use the custom formatter for horizontal and vertical tick labels
plt.XAxis.TickLabelFormat(customTickFormatter);
plt.YAxis.TickLabelFormat(customTickFormatter);

plt.SaveFig("asis_custom_tick_formatter.png");

Invert tick mark direction

Tick marks can be outward (default) or inverted to appear as inward lines relative to the edge of the plot area.

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

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

plt.XAxis.TickMarkDirection(outward: false);
plt.YAxis.TickMarkDirection(outward: false);

plt.SaveFig("ticks_invert_tick_mark_direction.png");