Treemaps

Overview

JavaScript Treemaps are a great way to display hierarchical (tree-structured) data by using nested rectangles. Each branch of the tree is given a rectangle, which is then tiled with smaller rectangles representing sub-branches. A leaf node's rectangle has an area proportional to a specified dimension on the data. It is also possible to color the leaf nodes to show a separate dimension of the data.

Unlike other JS charts, JavaScript treemaps use the children attribute to define the hierarchy and the value, value-size, and value-aspect attributes to define the data associated with the size and aspect of the rectangles.

{
  type: "treemap",
  series: [
    {
      text: "North America",
      children: [
        {
          text: "United States",
          children: [
            {
              text: "Texas",
              value: 21
            },
            ...
          ]
        }
      ]
    }
  ]
}

Data Format

Value Arrays

A single series array, with at least one object within it. Each object may have a children array of children objects, which may also include a children array of additional children objects, and so on.

{
series: [ // Array of objects
  {
    text:(Parent1), // String
    children: [ // Array of objects
      {
        text:(Parent1 -> Child1), // String
        value:val1 // Number
      },
      {
        text:(Parent1 -> Child2), // String
        children: [ // Array of objects
          {
            text:(Parent1 -> Child2 -> Child1), // String
            value:val1 //Number
          }
        ]
      }
    ]
  }
]
}

Aspect Types

The aspect-type attribute sets the aspect.

Random

The random attribute chooses a random palette used if the aspect-type is set to random.

{
  options: {
    'aspect-type': "random"
  }
}

Color Start/End

The color-start attribute sets the starting color of the color transition used when the aspect-type is set to transition. The color-end attribute sets the ending color of the color transition used when aspect-type is set to transition.

{
  options: {
    'aspect-type': "transition",
    'color-start': "#c00",
    'color-end': "#300"
  }
}

Palette

The palette attribute defines a custom palette used if the aspect-type is set to palette. It can hold an array of strings representing colors or an array of objects having various styling attributes, such as complex background colors, background images, or gradient definitions.

{
  options: {
    'aspect-type': "palette",
    palette: [ "#c98411", "#281300", "#991e00", "#470000", "#ff921f", "#feb950", "#704700", "#8a773c" ]
  }
}

JavaScript Rules

Define a function that returns an object containing styling attributes to be applied to each node.

{
  options: {
    'aspect-type': "myfunc()"
  }
}

Treemap-specific Properties

Treemaps include a number of unique chart-specific properties that allow you to manipulate its appearance and behaviors. They can be implemented into your chart by placing them within the options object.

{
  options: {
    'split-type': "balanced",
    'aspect-type': "palette",
    alpha-aspect: false,
    'thousands-separator': ", ",
    'decimals-separator': ".",
    decimals: "2",
    palette: [],
    min-alpha: .4,
    'color-start': "#336699",
    'color-end': "#99ccff",
    box: {},
    'tooltip-box': {},
    'hover-state': {}
  }
}

Box

The box attribute sets the styling for the treemap boxes (nodes).

{
  options: {
    box: {
      'border-color': "red"
    }
  }
}

Hover State

The hover-state attribute sets the styling for the hover-state of the boxes (nodes).

{
  options: {
    'hover-state': {
      alpha:1,
      'background-color': "black"
    }
  }
}

Split Type

The split-type attribute sets the splitting algorithm that draws the treemap. Changing this will adjust how the treemap displays the boxes. Set to balanced by default, you can change the value to: horizontal, vertical, balancedv2, squarify, squarifyv2, random, or alternate.

{
  options: {
        'split-type': "alternate" //balanced (default), balancedv2, horizontal, vertical, squarify, squarifyv2, random, alternate
      },
}

Alpha Aspect

The alpha-aspect attribute sets whether alpha will also be applied on the nodes based on the value-aspect values.

{
  options: {
    alpha-aspect: true
  }
}

Min Alpha

The min-alpha attribute sets the minimum value of the alpha applied to the nodes if alpha-aspect is set to true.

{
  options: {
    alpha-aspect: true,
    min-alpha:0.2,
  }
}

Max Children

The max-children attributes sets the maximum number of children each node can have.

{
  options: {
    'max-children': [8,2,4]
  }
}

Max Depth

The max-depth attribute sets the maximum depth. Child nodes with levels higher than this setting will be ignored.

{
  options: {
    'max-depth':2
  }
}

Tooltips

Tooltip Box

The tooltip-box attribute sets the styling for the tooltip that appears over the final nodes (without children).

{
  options: {
    'tooltip-box': {
      'background-color': "red",
      'text-align': "left"
    }
  }
}

Tooltip Group

The tooltip-group attribute sets the styling for the tooltip that appears over the nodes that have at least one child.

{
  options: {
    'tooltip-group': {
      'background-color': "red",
      'text-align': "left"
    }
  }
}

Summary

Got a question about how treemap charts work? We are happy to help. Email support@zingchart.com or start a chat right here on this page for help.