-----Original Message-----
From: g [mailto:gina.joue at ucd.ie]
Sent: Friday, 13 June 2003 10:12 AM
To: r-help at stat.math.ethz.ch
Subject: [R] formula (joint, conditional independence, etc.) -
mosaicplots
Hi,
Can someone set me straight as to how to write formulas in R
to indicate:
complete independence [A][B][C]
joint independence [AB][C]
conditional independence [AC][BC]
nway interaction [AB][AC][BC]
?
For example, if I have 4 factors:
hair colour, eye colour, age, sex
does
> mosaicplot( frequency ~ hair + eye + age + sex)
mean that the model fitted is of complete independence of all factors
[hair][eye][age][sex]?
So does
> mosaicplot(frequency ~ hair + eye)
mean that the model is of conditional independence
[hairAgeSex][eyeAgeSex]?
How does the operator * as in
> mosaicplot( frequency ~ hair * eye)
> mosaicplot( frequency ~ hair * eye + age)
equate to in the type of independence model used?
Thanks in advance for any elucidation!
Gina