"V&R's MASS book" can you give the full name of that book
--- On Thu, 3/7/08, Bert Gunter <[EMAIL PROTECTED]> wrote:
From: Bert Gunter <[EMAIL PROTECTED]>
Subject: RE: [R] A regression problem using dummy variables
To: [EMAIL PROTECTED]
Cc: r-help@r-project.org
Dat
sorry, made a stupid mistake.
I got it.
thanks a lot!
Peter Dalgaard wrote:
>
> rlearner309 wrote:
>> I think it is zero, because you have lots of zeros there. It is not like
>> continous variables.
>>
>>
> Think again. The sum of products may be zero, but that is not the
> covariance. And
09; Peter Dalgaard
Cc: r-help@r-project.org
Subject: Re: [R] A regression problem using dummy variables
"which group contrasts you want to look at" can you clarify me on that
statement?
--- On Thu, 3/7/08, Peter Dalgaard <[EMAIL PROTECTED]> wrote:
__
"which group contrasts you want to look at" can you clarify me on that
statement?
--- On Thu, 3/7/08, Peter Dalgaard <[EMAIL PROTECTED]> wrote:
From: Peter Dalgaard <[EMAIL PROTECTED]>
Subject: Re: [R] A regression problem using dummy variables
To: "rlearner309"
rlearner309 wrote:
I think it is zero, because you have lots of zeros there. It is not like
continous variables.
Think again. The sum of products may be zero, but that is not the
covariance. And don't dismiss Thomas, he is usually right.
Anyways, the coefs of dummy variables represent dif
I think it is zero, because you have lots of zeros there. It is not like
continous variables.
Thomas Lumley wrote:
>
> On Wed, 2 Jul 2008, rlearner309 wrote:
>
>>
>> I think the covariance between dummy variables or between dummy variables
>> and
>> intercept should always be zero. meaning:
On Wed, 2 Jul 2008, rlearner309 wrote:
I think the covariance between dummy variables or between dummy variables and
intercept should always be zero. meaning: no sigularity problem??
No. You can easily check that this is not true using the cov() function.
Indicator variables for mutually
I think the covariance between dummy variables or between dummy variables and
intercept should always be zero. meaning: no sigularity problem??
rlearner309 wrote:
>
> This is actually more like a Statistics problem:
> I have a dataset with two dummy variables controlling three levels. The
>
Yes. Because the slopes are supposed to be the same.
Level shifts are needed to be modeled.
Moshe Olshansky-2 wrote:
>
> Do you have a reason to treat all 3 levels together and not have a
> separate regression for each level?
>
>
> --- On Tue, 1/7/08, rlearner309 <[EMAIL PROTECTED]> wrote:
>
Do you have a reason to treat all 3 levels together and not have a separate
regression for each level?
--- On Tue, 1/7/08, rlearner309 <[EMAIL PROTECTED]> wrote:
> From: rlearner309 <[EMAIL PROTECTED]>
> Subject: [R] A regression problem using dummy variables
> To: r-help@r-project.org
> Recei
10 matches
Mail list logo
