LISTSERV at the University of Georgia
Menubar Imagemap
Home Browse Manage Request Manuals Register
Previous messageNext messagePrevious in topicNext in topicPrevious by same authorNext by same authorPrevious page (November 2008, week 2)Back to main SAS-L pageJoin or leave SAS-L (or change settings)ReplyPost a new messageSearchProportional fontNon-proportional font
Date:         Mon, 10 Nov 2008 17:03:59 -0800
Reply-To:     stringplayer_2@yahoo.com
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Dale McLerran <stringplayer_2@YAHOO.COM>
Subject:      Re: SAS wald test
In-Reply-To:  <53406d55-68a1-4bf4-a1d1-0b7bb2d1be1c@g17g2000prg.googlegroups.com>
Content-Type: text/plain; charset=us-ascii

--- On Mon, 11/10/08, clyde013@YAHOO.COM <clyde013@YAHOO.COM> wrote:

> From: clyde013@YAHOO.COM <clyde013@YAHOO.COM> > Subject: Re: SAS wald test > To: SAS-L@LISTSERV.UGA.EDU > Date: Monday, November 10, 2008, 4:53 PM > On Nov 10, 1:20 pm, stringplaye...@yahoo.com (Dale McLerran) > wrote: > > --- On Mon, 11/10/08, clyde...@YAHOO.COM > <clyde...@YAHOO.COM> wrote: > > > > > > > > > > > > > From: clyde...@YAHOO.COM > <clyde...@YAHOO.COM> > > > Subject: SAS wald test > > > To: SA...@LISTSERV.UGA.EDU > > > Date: Monday, November 10, 2008, 9:35 AM > > > I have one data set consisting of 2 groups. > Group 1 f=1 and > > > Group 2 > > > f=0. I am looking to compare parameter estimates > for these > > > two groups > > > with a Wald Chi-square test statistic. Can > someone specify > > > how I'd go > > > about doing that? > > > > > For example, right now my code for the regression > looks > > > like this: > > > > > proc reg data=gg11; > > > model retpi = dummy; by f; run; > > > > > what I need to do is compare the coefficient on > dummy for > > > when f=1 and > > > when f=0 using a wald test. Thanks in advance for > any help! > > > > Clyde, > > > > This appears to be some sort of homework problem, so I > won't > > give you all the details of how to get a Wald > chi-square test. > > However, I feel it is safe to provide some direction > for where > > to look. Take a look at the documentation of the > GENMOD > > procedure, and especially at the sections > > > > SYNTAX --> MODEL Statement > > DETAILS --> Type 3 Analysis > > > > Good luck, > > > > Dale > > > > --------------------------------------- > > Dale McLerran > > Fred Hutchinson Cancer Research Center > > mailto: dmclerra@NO_SPAMfhcrc.org > > Ph: (206) 667-2926 > > Fax: (206) 667-5977 > > ---------------------------------------- Hide quoted > text - > > > > - Show quoted text - > > > Thanks. I tried the following code and am still getting > the wrong > statistic. What am i forgetting?? > > proc genmod data=gg11; > class f; > model retpi=dummy /type3 wald ;run; > > Is this doing what I need it to be? Is it comparing the > parameter > estimate on the dummy variable for class f=1 to f=0??

Clyde,

You are close. I think I can assist further. You have named f on the CLASS statement. But where does f appear in your model?

Additional hint: you need to compare both intercept and slope parameters, right? So f needs to modify two parameters of your model. How can you get f to modify both slope and intercept?

HTH,

Dale

--------------------------------------- Dale McLerran Fred Hutchinson Cancer Research Center mailto: dmclerra@NO_SPAMfhcrc.org Ph: (206) 667-2926 Fax: (206) 667-5977 ---------------------------------------


Back to: Top of message | Previous page | Main SAS-L page