Multiple 2D color planes will be stacked on text to each other like books on a self to form a color cube. The following explanation will walk you through this process of transformation. The color cube at the end will look like this:
Let's look at our plant growth example again, Figure 4. When the experiment is run with different rates of fertilizer application, we generate multiple 2D graphs. For example, they might look something like this.
All of the 2D graphs are then converted into 2D color plans as previously explained. To Go Back and Review Click Here These graphs would then look like this:
The color plans are then stacked next each other, like books on a shelf, to form a cube of color. The color plans are stacked in order and the second axis is formed from the variable that is ordered. In this example the new axis represents the rate of fertilizer application. Remember that the color represents plant growth.
On one axis would be the amount of water, on the second axis the amount of sunlight, and on the third axis the rate of fertilizer application.
We can slice the cube in three different ways. Each time we slice it we could see how two of the variables change as one is fixed. If we take a slice where the sunlight is 10 hours per day, then we would get a single plane of color that shows how the plant growth changes with water and rate of fertilizer application, since we are holding sunlight fixed. The second way to slice the cube is keeping water fixed, which shows how plant growth changes as effected by sun and rate of fertilizer application. The third slice possible would be to hold the rate of fertilizer application fixed and view the effect of the amount of sun and the amount of water on plant growth.
A cut where water is held constant and one would see the 2D color plane with rate of fertilizer application and sun on the axises of the slice.
A cut where the rate of fertilizer application is held constant and one would see the 2D color plane with water and sun on the axises of the slice.
The following movie shows the process of going multiple color plans to a single 3D graph, with three independent variables and the dependent variable represented by color.
Last revised July 13, 1996
http://www.sv.vt.edu/class/surp/surp96/laughlin/stat/3D_tutor/color_cube.html