I am trying to find any interaction between independent variables in Group and 2 samples of dependent variables Level1 and Level2 in my data dataset (size reduced).
Group Level1 Level2
a 1 0
a 2 3
a 4 3
b 2 4
b 1 3
b 3 2
c 2 4
c 3 2
c 1 3
For this, I want to run a manova test.
However when I am trying to run manova(data[,2:3] ~ as.factor(Group), data=data), I get invalid type (list) for variable 'data[,2:3]' error although data[,2:3] IS a list.
(Obviously this is my first time trying to use manova and basically R for this task and I have very basic knowledge of R so maybe I am completely wrong in what I am doing in general).
You need to run it like this using cbind:
Data
df <- read.table(header=T, text='Group Level1 Level2
a 1 0
a 2 3
a 4 3
b 2 4
b 1 3
b 3 2
c 2 4
c 3 2
c 1 3')
Solution:
> manova( cbind(Level1,Level2) ~ Group, data=df)
Call:
manova(cbind(Level1, Level2) ~ Group, data = df)
Terms:
Group Residuals
resp 1 0.222222 8.666667
resp 2 2 10
Deg. of Freedom 2 6
Residual standard errors: 1.20185 1.290994
Estimated effects may be unbalanced