R help - Jun 2004 - lda

I am trying to write the following code in R.  The code works in S+ and i 
am trying to do the program in R.

x=discrim(admit~gpa+gmat,prior=c("uniform"),data=data.mm)

i wrote the following in R:

x=lda(admit~gpa+gmat,data=data.mm)

i could not figure out how to write prior=c("uniform") in R.  I would
get
an error every time.  I think that it has something to do 
with "uniform".  Do you know what i use instead of "uniform"
for R?  I am
trying to do a uniform distribution.
Thank you.

> i could not figure out how to write prior=c("uniform") in R.  I
would get
> an error every time.  I think that it has something to do
> with "uniform".  Do you know what i use instead of
"uniform" for R?  I am
> trying to do a uniform distribution.
try ?runif  (random uniform distribution)

There is a help page for lda: please read it for yourself (as the posting
guide requests you too).  lda in R works the same way in R as it works in
S-PLUS: in both it is support software for a book, and the posting guide
also asks you to read that book.


On Sat, 12 Jun 2004, Martin Willett wrote:
> 
> I am trying to write the following code in R.  The code works in S+ and i 
> am trying to do the program in R.
> 
> x=discrim(admit~gpa+gmat,prior=c("uniform"),data=data.mm)
> 
> i wrote the following in R:
> 
> x=lda(admit~gpa+gmat,data=data.mm)
> 
> i could not figure out how to write prior=c("uniform") in R.  I
would get
> an error every time.  I think that it has something to do 
> with "uniform".  Do you know what i use instead of
"uniform" for R?  I am
> trying to do a uniform distribution.
-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

Seems rather straightforward to me.  The prior="uniform" in discrim()
says
to use equal prior for each group.  You can do the same by explicitly
specifying the priors; e.g.,

x <- lda(admit ~ gpa + gmat, data=data.mm, 
         prior=1/nlevels(data.mm$admit))

HTH,
Andy
> From: Martin Willett
> 
> I am trying to write the following code in R.  The code works 
> in S+ and i 
> am trying to do the program in R.
> 
> x=discrim(admit~gpa+gmat,prior=c("uniform"),data=data.mm)
> 
> i wrote the following in R:
> 
> x=lda(admit~gpa+gmat,data=data.mm)
> 
> i could not figure out how to write prior=c("uniform") in R.  
> I would get 
> an error every time.  I think that it has something to do 
> with "uniform".  Do you know what i use instead of
"uniform"
> for R?  I am 
> trying to do a uniform distribution.
> Thank you.