Date: Tue, 30 Oct 2007 23:33:56 -0000
Sender: "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From: Matthew <matthewpharr@GMAIL.COM>
Subject: Convert Discriminant Score to Probability
Content-Type: text/plain; charset="iso-8859-1"
I have run a discriminant analysis in SPSS and would like to use the
score to transform the prior probabilities to posterior probabilities.
run a discrim against a 7 level target. However, I need to score a
dataset with the equation I created. I would like to not only have the
in my different dataset but also the probability that SPSS produces. I
problem computing a score with the discrim equation using Fisher's
classification function. If I score a new record that hits my database
with the 7 level discrim equation, I get seven scores
for that record. I would also like to get 7 new variables that track
probability of being in each group (summing all probabilities would
1). Has anyone encountered a task like this? I know SPSS uses Bayes'
to do this, but I can't quite get the formula to work on my new
Also, I have to transport this solution into another application. I
bring my new data back into SPSS and run the discrim again. Thanks in
advance for any help provided.