Treemap Overview
Structure
Treemaps represent tree nodes as
rectangles. In a treemap, a node’s
rectangle contains any children it has.
Treemap Panel
Here are some operations you can perform on the
Treemap Panel (left):
|
Operation |
Action |
|
View attribute values
for a particular node |
Single left click
on the node |
|
Zoom in
on a particular node |
Double left click
on the node |
|
Zoom out
by one level |
Single right click
on any node |
Attribute Panel
The Attribute Panel (upper right) contains a
table with the attribute values on the most recent node that you single left
clicked. For each Unit node, the table
contains the name and size of the node, as well as values for Output, (number
of Problems), and Health. For each
State and County node, the table contains the name and size of the node, but
the other values are all zero. Node
size is determined by the value of the attribute selected in the “Size” combo
box under the Filters tab. (If the
selected attribute is “(None)” then each Unit node gets size 1.) For internal nodes, size is the sum of
its children’s sizes.
Control Panel
The Control Panel (bottom right) allows you to
focus on specific data by sizing, filtering, and coloring. For example, to identify which unit has the
greatest number of problems today, you could do the following:
1. (Sizing)
Change the “Size” combo box to “Problems.”
2. (Filtering)
Move the left handle of the “Problems” double-slider bar under the “Filters”
tab to the right until only you gray-out all but a few units. Units that are dark gray on the treemap fall
into the dark gray areas of at least one double-slider bar.
3. (Filtering)
Click the “Hide” button. The node with
the greatest number of problems is the largest node in the treemap (Unit92).
Similarly, you can use coloring:
1. Reset all size, color, and filter settings by
clicking the “Reset legend and filters” button under the “Main” tab.
2. (Filtering) Under the “Legend” tab, select “Problems” in the “Color” combo box. The node with the greatest number of problems is the brightest green node in the treemap (Unit92).