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c#windowschartsdata-visualizationaxes
Ricky Robinson
Ricky Robinson

Reputation: 22893

C#, DataVisualization.Charting: assign custom labels to values on axes

In C# I am using the DataVisualization.Charting library for plotting. In a simple line graph, I would like to show some custom text on the x-axis on positions x=0, 1, 2, 3.

Something like this (in matplotlib, though): enter image description here

This is the documentation for Axis class, but I'm not sure what I should look for.

Upvotes: 0

Views: 5892

Answers (4)

Stefan Thordarson
Stefan Thordarson

Reputation: 31

I stumbled into this thread, while searching for an solution on similar problem - I wanted a simple solution to have total control over the labels on the primary X-axis.

All I needed, was to use CustomLabels, example :

double mPtr = 0.0;
double stepMeter = 1000;
double distanceMeter = 14200;
while (mPtr < distanceMeter)
{
    var customLabel = new CustomLabel();
    customLabel.FromPosition = mPtr - stepMeter / 3;
    customLabel.ToPosition = mPtr + stepMeter / 3;
    customLabel.Text = $"{(mPtr / 1000.0):f1} km";

    chart1.ChartAreas[0].AxisX.CustomLabels.Add(customLabel);

    mPtr += stepMeter;
}

enter image description here

By the way, currently I am using this Nuget package [https://github.com/kirsan31/winforms-datavisualization], VS2002 / .NET 7. Contains great performance improvements.

Upvotes: 1

Vojtěch Dohnal
Vojtěch Dohnal

Reputation: 8104

Use the AxisLabel property of DataPoint. Description of AxisLabel property:

Gets or sets the text of the X-axis label for the data point, series or an empty point. This property is only used if a custom label has not been specified for the relevant Axis object.

So your code can look like this:

DataPoint dp1 = new DataPoint(1, 1);
dp1.AxisLabel = "Frogs";
DataPoint dp2 = new DataPoint(2, 4);
dp2.AxisLabel = "Hogs";
DataPoint dp3 = new DataPoint(3, 9);
dp3.AxisLabel = "Bogs";
DataPoint dp4 = new DataPoint(4, 6);
dp4.AxisLabel = "Slogs";
chart1.Series[0].Points.Add(dp1);
chart1.Series[0].Points.Add(dp2);
chart1.Series[0].Points.Add(dp3);
chart1.Series[0].Points.Add(dp4);

Or you can enforce 1=Frogs, 2=Hogs, 3=Bogs and 4=Slogs with following code:

chart1.ChartAreas[0].AxisX.MajorGrid.Enabled = false;
chart1.ChartAreas[0].AxisY.MajorGrid.Enabled = false;    
chart1.Series[0].MarkerStyle = MarkerStyle.Circle;
chart1.Series[0].MarkerBorderColor = System.Drawing.Color.Black;
chart1.Series[0].MarkerColor = System.Drawing.Color.Red;
chart1.Series[0].Points.AddXY(1, 1);
chart1.Series[0].Points.AddXY(2, 4);
chart1.Series[0].Points.AddXY(3, 9);
chart1.Series[0].Points.AddXY(4, 6);
foreach (DataPoint dp in chart1.Series[0].Points)
{
    switch ((int)dp.XValue)
    {
        case 1: dp.AxisLabel = "Frogs"; break;
        case 2: dp.AxisLabel = "Hogs"; break;
        case 3: dp.AxisLabel = "Bogs"; break;
        case 4: dp.AxisLabel = "Slogs"; break;
    }
}

To achieve really the same as on the picture - axes on both sides - you would need to use the following trick.

It works for X axis only, for Y axis you can add custom labels as described here.

You can also use labels of datapoints which appear inside the chart using IsValueShownAsLabel.

Upvotes: 2

mmathis
mmathis

Reputation: 1610

Just add your points with those labels as the x values:

chart1.Series[0].Points.AddXY("Frogs", 1);
chart1.Series[0].Points.AddXY("Hogs", 4);
// etc

Or, you could databind the points using two arrays:

string[] xvalues = new [] {"Frogs", "Hogs", "Bogs", "Slogs"};
int[] yvalues = new [] {1, 4, 9, 6};
chart1.Series[0].Points.DataBindXY(xvalues, yvalues);

Upvotes: 1

Deeko
Deeko

Reputation: 1539

You need to set the "Format" property of the LabelStyle on your axis.

See: http://msdn.microsoft.com/en-us/library/system.web.ui.datavisualization.charting.labelstyle(v=vs.110).aspx

There's a few reasonable tutorials on using the charting library out there if you search for them. Here's one: http://weblogs.asp.net/dwahlin/getting-started-with-the-asp-net-3-5-chart-control

Upvotes: 0

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