Polar Chart

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A polar chart is a type of chart that displays two-dimensional data that is displayed on a polar coordinate system. In this system the X value represents an angle and the Y value represents a distance from the polar coordinate system origin. The following picture shows a typical polar chart:

Creating a Polar Chart

To create a polar chart you need to create an instance of the NPolarChart type and add it to the chart surface. The following code shows how to create a polar chart containing one series with three data points:

C#	Copy Code
// Add a NOV widget inside the form NChartView chartView = new NChartView(); // create a dock panel with a label and chart NDockPanel dockPanel = new NDockPanel(); chartView.Surface.Content = dockPanel; // craete a docked label NLabel label = new NLabel(); label.Text = "My First Polar Chart"; label.Margins = new NMargins(10); label.Font = new NFont(NFontDescriptor.DefaultSansFamilyName, 12); label.TextFill = new NColorFill(NColor.Black); label.TextAlignment = ENContentAlignment.MiddleCenter; NDockLayout.SetDockArea(label, ENDockArea.Top); dockPanel.AddChild(label); // create a new polar chart NPolarChart polarChart = new NPolarChart(); polarChart.Margins = new NMargins(10); NDockLayout.SetDockArea(polarChart, ENDockArea.Center); dockPanel.AddChild(polarChart); polarChart.SetPredefinedPolarAxes(ENPredefinedPolarAxes.AngleValue); // create a polar point series NPolarPointSeries point = new NPolarPointSeries(); point.DataPoints.Add(new NPolarPointDataPoint(70, 10)); point.DataPoints.Add(new NPolarPointDataPoint(150, 20)); point.DataPoints.Add(new NPolarPointDataPoint(240, 30)); polarChart.Series.Add(point);

Copy Code

// Add a NOV widget inside the form
NChartView chartView = new NChartView();
// create a dock panel with a label and chart
NDockPanel dockPanel = new NDockPanel();
chartView.Surface.Content = dockPanel;
// craete a docked label
NLabel label = new NLabel();
label.Text = "My First Polar Chart";
label.Margins = new NMargins(10);
label.Font = new NFont(NFontDescriptor.DefaultSansFamilyName, 12);
label.TextFill = new NColorFill(NColor.Black);
label.TextAlignment = ENContentAlignment.MiddleCenter;
NDockLayout.SetDockArea(label, ENDockArea.Top);
dockPanel.AddChild(label);
// create a new polar chart
NPolarChart polarChart = new NPolarChart();
polarChart.Margins = new NMargins(10);
NDockLayout.SetDockArea(polarChart, ENDockArea.Center);
dockPanel.AddChild(polarChart);
polarChart.SetPredefinedPolarAxes(ENPredefinedPolarAxes.AngleValue);
// create a polar point series
NPolarPointSeries point = new NPolarPointSeries();
point.DataPoints.Add(new NPolarPointDataPoint(70, 10));
point.DataPoints.Add(new NPolarPointDataPoint(150, 20));
point.DataPoints.Add(new NPolarPointDataPoint(240, 30));
polarChart.Series.Add(point);

Like in the case of the Cartesian chart you can take advantage of the SetPredefinedPolarAxes method that initializes a set of value and angle axes. The following table lists the available options:

ENPredefinedPolarAxes	Description
AngleValue	Represents a polar chart with two axes - one value axis and one angle axis
AngleValueSecondaryValue	Represents a polar chart with three axes - two value axes and one angle axis
AngleSecondaryAngleValue	Represents a polar chart with three axes - two angle axes and one value axis

By default, all polar series are configured to use X values from data points (e.g. have their UseXValues property set to true).