Overview
Overview
A radar chart is a graphical method of displaying multivariate data in the form of a two-dimensional chart of three or more quantitative variables represented on axes starting from the same point. The relative position and angle of the axes is typically uninformative.
The radar chart is also known as a web chart, spider chart, star chart, cobweb chart, star plot, irregular polygon or kiviat diagram.
Chart
AnyChart JavaScript charting library allows to display three types of series on Radar chart: Line, Area and Marker. You need to create chart using radar() method to display Radar chart:
// chart type
chart = anychart.radar();
// series type and data setting
chart.line([
{x: "Administration", value: 22},
{x: "Sales", value: 34},
{x: "Marketing", value: 16},
{x: "Research", value: 12},
{x: "Support", value: 38},
{x: "Development", value: 47}
]);
As you can see each point is represented with x and value fields.
Here is a basic Radar sample:
Configuration
Radar chart has several distinctive configuration options, which are presented in section "Chart rotation and background settings".
Start angle
By default radar starts drawing from the top center point (0°), but you can change this using startAngle() parameter:
chart.startAngle(90);
Here is the radar chart sample with starting angle shifted to 90°:
Plot background
You can change radar background using background() method, learn more about this method at Background settings tutorial.
var background = chart.background();
// enables background
background.enabled(true)
background.fill({
// set gradient colors
keys: [".1 white", ".7 gray", ".9 darkgray"],
// set angle of colors drawing
angle: -130
});
Here is a Radar chart with tuned background:
Axes
In AnyChart axis is an object that allows you to configure chart grid, axis line along with tick marks and labels, axis scale and settings and else. All axis features are described in Axes Basics tutorial.
Stroke
Axis stroke appearance is controlled by stroke() parameter.
// set chart type
var chart = anychart.radarChart();
// adjust y axis visualization
var yAxis = chart.yAxis();
// set stroke thickness equal to 2px and set custom stroke color
yAxis.stroke("2 #9900FF");
More information about possible stroke settings can be found in Strokes and Lines tutorial.
Here is a sample of a chart with tuned X and Y axes. Y-axis dashed stroke and X-axis has a stroke colored with gradient.
Inversion
AnyChart allows to invert any axis. Inversion is controlled by axis inverted() method:
var yScale = chart.yScale();
yScale.inverted(true);
Look at the demonstration of Y-Axis inversion in the sample below:
Logarithmic Scale
You can set a logarithmic scale type using scale() method. More information about scale types can be found in Scale tutorial
// create logarithmic scale
var logScale = anychart.scales.log();
// set minimum and maximum value for the scale
logScale.minimum(10);
logScale.maximum(10000);
// set logarithmic scale as y scale for the chart
chart.yScale(logScale);
Here is the demonstration of Logarithmic Y-Axis on a simple radar with area series:
Stacked Mode
Multiple area series can be presented with usage of stacked mode for Y scale. Stacked mode helps to visualize data in a convenient way for comparing different data series which share one of the values. Use stackMode() parameter to enable stacked mode.
// set chart type
var chart = anychart.radarChart();
// set stacked mod
var yScale = chart.yScale();
yScale.stackMode("value");
Percent stacked mode calculates the proportion of each point to the category sum and uses this percentage as a value. To enable this mode set stackMode("percent").
Labels Settings
You can easily tune visual appearance of axes' labels as well as adjust labels' length.
In the sample below all names are limited to the length of 3:
// chart type
var chart = anychaty.radarChart();
var xLabels = chart.xAxis().labels();
xLabels.useHtml(true);
// set labels content
xLabels.format("<b>{%Value}</b>");
You can change labels' background. Learn more about background configuration in Background settings tutorial.
var xLabels = chart.xAxis().labels();
// set paddings for labels
xLabels.padding(5);
// set font weight for labels
xLabels.fontWeight(900);
// axes background settings
var labelsBackground = chart.xAxis().labels().background();
// enable background
labelsBackground.enabled(true);
// background fill
labelsBackground.fill("lightblue");
// stroke color
labelsBackground.stroke("blue");
// corner type
labelsBackground.cornerType("round");
// corner size
labelsBackground.corners(5);
You can hide the first and/or the last use of labels drawFirstLabel() and drawLastLabel() parameters:
// adjust y axis settings
var yAxis = chart.yAxis();
// disable first label
yAxis.drawFirstLabel(false);
// disable last label
yAxis.drawLastLabel(false);
Visualization
Grid
Radar grid is a combination of circular and radial grids. Grid visual appearance can be set using several methods:
// chart type
var chart = anychart.radarChart();
var grid = chart.grid(0);
// color odd cells in the grid
grid.oddFill("red");
// color even cells in the grid
grid.evenFill("darkred");
// set layout type
grid.layout("radial");
Note: full information on grid settings can be found in Grid section of Axes tutorial
Sample below demonstrates two radar charts with adjusted visualisation of the radial type of grid as well as of the circular one.
Labels and Tooltips
In this section we will explain how to add and configure data labels and tooltips.
If you want to configure data labels and tooltips for all series - you should do that in labels() and tooltip() methods. You can tune visual appearance, positioning and format of labels and tooltips.
// chart type
var chart = anychart.radarChart();
// setting data
var series = chart.area(data);
// setting labels
var labels = series.labels();
// enables labels
labels.enabled(true);
// setting content
labels.format(function(point){
return point.x;
});
// setting tooltips
var tooltip = series.tooltip();
// setting content
tooltip.format("{%x}");
Sample below has more complex tooltip than snippet above. Click 'Launch in playground' to see format settings of a tooltip.
Series Types
Radar js graphs supports Line, Area and Marker series types. You can learn how to change and configure styles of these types at: Area chart, Line chart and Marker chart.