Examine Patterns in Car Safety

This example uses the Cars.jmp sample data table, which contains impact measurements of crash-test dummies in automobile safety tests. Compare these measurements for different automobile makes and models during the years 1990 and 1991.

Select Help > Sample Data Library and open Cars.jmp.

Filter the data to show only the years 1990 and 1991 and create a subset of the Cars.jmp data table.

Select Rows > Data Filter.

Select Year.

Click Add.

Select 90 and 91 (hold down the Shift key).

The rows corresponding to 1990 and 1991 are highlighted in the data table.

In the data table, select Tables > Subset.

Ensure that Selected Rows is selected and click OK.

A new data table (Subset of Cars) appears that contains only the data corresponding to the years 1990 and 1991.

Now, using the Subset of Cars data table, create the treemap.

Select Graph > Legacy > Treemap.

Select Wt (weight) and click Sizes.

Select Make and Model and click Categories.

Select L Leg and click Coloring.

L Leg represents a measurement of injuries resulting from the deceleration speed of the left leg, where more deceleration causes more injury.

Click OK.

The report window appears.

Figure 11.19 Left Leg Deceleration Injuries

From Figure 11.19, you can see that the Club Wagon and S10 Pickup 4x4 have the largest number of left leg deceleration injuries.

You can examine other safety measurements without re-launching the Treemap platform, as follows:

From the red triangle menu, select Change Color Column.

Select Head IC.

Click OK.

The treemap updates to reflect head injuries instead of left leg injuries.

Figure 11.20 Head Injuries

From Figure 11.20, you notice the following:

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Although the S10 Pickup 4x4 had a high number of left leg deceleration injuries, it has a lower number of head injuries.

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The Club Wagon still has a high number of head injuries, in addition to the high number of left leg deceleration injuries.

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The Trooper II 4x4 had a low number of left leg deceleration injuries, but it has a high number of head injuries.