Date: Wed, 17 Jan 2007 23:31:51 -0800
Reply-To: David L Cassell <davidlcassell@MSN.COM>
Sender: "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From: David L Cassell <davidlcassell@MSN.COM>
Subject: Re: problem of parametric trend test
In-Reply-To: <200701180709.l0I1FZ7v017959@malibu.cc.uga.edu>
Content-Type: text/plain; format=flowed
ankur.arora@NAGARRO.COM wrote back:
>Original Message:
>-----------------
>From: David L Cassell davidlcassell@MSN.COM
>Date: Wed, 17 Jan 2007 22:27:36 -0800
>To: SAS-L@LISTSERV.UGA.EDU
>Subject: Re: problem of parametric trend test
>
>
>ankur.arora@NAGARRO.COM wrote:
> >
> >Hi All,
> >
> >
> >I want to perform parametric trend test in sas.
> >
> >Can anybody advise how to perform the parametric trend test in sas.
> >
> >Thanks in advance.
> >
> >Thanks
> >Ankur
>
>There is no single "the parametric trend test", unfortunately. And if
>there were only one, it probably wouldn't work for most data sets. :-(
>
>So you need to describe your data and meta-data in a lot more detail,
>with some discussion on the overall goal here, so we have some idea of
>what kind of test is likely to be reasonable.
>
>Then you would end up having to check the assumptions of whatever
>test gets recommended, and decide if the test can even be applied
>to your data.
>
>HTH,
>David
>--
>David L. Cassell
>mathematical statistician
>Design Pathways
>3115 NW Norwood Pl.
>Corvallis OR 97330
>
>Hi David,
>
>I have a dataset like this
>
>group Independent variable
>
>1 123
>1 124
>1 122
>2 123
>2 111
>2 123
>3 123
>3 123
>3 344
>4 123
>4 234
>
>so my class the variable is group.
>
>1) I had one option with proc logistics
>
>proc logistic;
>model GROUP(order=internal ref="1")=var to be analysed /
>link=glogit risklimits;
>run;
>
>1 :is the control group
>so basically finding trend by comparing with the control group.
>
>2) option is to use proc reg with contrast statement
>but here we are not specifying any control group
>
>how do i generate the contrast coeficient acording to no of groups
>because i need to program a macro where no of groups can change
>so i need to generate contrast statement at run time.
>
>I am confused how to calculate the trend.
>could you throw light on how to do parametric trend statistically.
>
>so how do I set the parametric trend.
>
>Thanks
>Ankur
>
So far, your code does not make much sense.
You need to explain why you are interested in a trend test, and
why you want something like PROC LOGISTIC, which I think is
getting you farther and farther form where you want to be.
I cannot figure out any reason why you would want GROUP
to be your dependent variable here, so either I do not understand
your goals, or you are really far off-track now.
I need you to explain what you want to do, and I need you to
explain in detail, not just show the same old (example) data set
to us. Please write back to SAS-L and explain what the larger goal
of this process really is, and why you are insistent on a trend test
when you have small sets of numbers for each separate value of
group.
HTH,
David
--
David L. Cassell
mathematical statistician
Design Pathways
3115 NW Norwood Pl.
Corvallis OR 97330
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