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Re: ANOVA with empty cells
From: |
Mike Miller |
Subject: |
Re: ANOVA with empty cells |
Date: |
Mon, 11 Apr 2005 12:54:50 -0500 (CDT) |
On Mon, 11 Apr 2005, Isaac Neuhaus wrote:
How does SAS do it?
Source DF Type III SS Mean Square F Value Pr > F
R 3 36.30000000 12.10000000 48.40 0.0203
T 1 4.08333333 4.08333333 16.33 0.0561
R*T 1 0.75000000 0.75000000 3.00 0.2254
You'll have to look at their manuals to figure out what they are doing.
Note that you have 3 df for R, 1 df for T, but only one df for R*T. It
must be fitting a model with a sort of partial interaction effect. In a
full model, you would have 3*1 = 3 df for interaction.
Looking more closely, you can only fit an interaction to the part of the
model where f1 is 1 or 3. So that must be what it is doing. You can do
this in Octave using dummy codes. You need three dummy codes for f1, one
for f2, and one for (arbitrary choice here) when f1=1, f2=1. Once you
have that done, you can use the '\' operator and other functions to solve
this, but I'm sure someone has developed a little regression or ANOVA
package to make this easier.
Mike
Your data....
f1 f2 response
S1 1 1 7
S2 2 1 1
S3 3 1 4
S4 4 2 5
S5 3 2 5
S6 1 2 9
S7 3 2 5
S8 1 2 10
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- ANOVA with empty cells, Isaac Neuhaus, 2005/04/11
- Re: ANOVA with empty cells, Mike Miller, 2005/04/11
- Re: ANOVA with empty cells, Isaac Neuhaus, 2005/04/11
- Re: ANOVA with empty cells,
Mike Miller <=
- Re: ANOVA with empty cells, Isaac Neuhaus, 2005/04/11
- Re: ANOVA with empty cells, Mike Miller, 2005/04/11
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- Re: ANOVA with empty cells, Mike Miller, 2005/04/11
- Re: ANOVA with empty cells, Isaac Neuhaus, 2005/04/11
- ANOVA with empty cells, Isaac Neuhaus, 2005/04/12