Question on 3D-Contour Diagram in Minitab

[nonw1988]

Hey guys,

I have done an experiment with three different factors on three different levels. I entered the information into the reponds and would like to create a diagram, which shows all three factors and the respond as a 3D contour,
similar to the 2D contour diagram I managed to find, but in three dimensional plane.

Is this possible in Minitab? The only thing I found so far is A,B and Y in one, but not all four.

I hope I made myself clear.



A B C Responds (Y)
8 6 40 7,7
8 6 50 7,2
8 6 75 6,8
8 8 40 13,8
8 8 50 12,4
8 8 75 12,6
8 10 40 18,4
8 10 50 16,3
8 10 75 14,3
10 6 40 8,1
10 6 50 9,2
10 6 75 *
10 8 40 13,6
10 8 50 12,6
10 8 75 18,1
10 10 40 18,0
10 10 50 12,9
10 10 75 12,9
12 6 40 7,3
12 6 50 7,0
12 6 75 3,5
12 8 40 16,5
12 8 50 17,1
12 8 75 11,8
12 10 40 8,4
12 10 50 17,2
12 10 75 15,4

 

[Miner]

The only way to do it using contour plots is to plot Y against A & B, then against A & C then against B & C.

However, it is unnecessary to all of these as B is the only factor that is statistically significant. A simple main effects plot is sufficient.

 

[nonw1988]

Hmm thats too bad. Would have been interesting to see the change of respond depending on all three factors in one graph. I just asked because even Microsoft Excel is able to do that.

But considering that this isn't possible I have another question. In case of the 2D-Graphes for example A vs B showing Y in different colours, what happens to C in this case? Which value does Minitab use of factors not being displayed?

 

[Miner]

Minitab allows you to specify at what level C is held constant. I believe that the default level is the mid point of the three levels.

I am curious as to how Excel can display three factors and an interaction in a single graph.

 

[nonw1988]

Excels approach to display all four dimensions is similar to the one of Minitab in case of the 2D graphes. The x, y and z axes represent the Factors A,B and C. The fourth dimension (Responds) is shown by the use of different colors.