On Jan 30, 2013, at 04:58 , Bert Gunter wrote:
> You almost never need dummy variables in R. R creates them
> automatically from factors given model and possibly contrasts
> specification.
>
> ?contrasts ## for some technical details.
>
> If you have not read "An Introduction to R" do so now.
You almost never need dummy variables in R. R creates them
automatically from factors given model and possibly contrasts
specification.
?contrasts ## for some technical details.
If you have not read "An Introduction to R" do so now. Pay particular
attention to the chapter on modeling and categor
Is your variable Clarity a categorical with 4 levels? Thus, the need for
k-1 (3) dummies? Your error may be the result of creating k instead of
k-1 dummies, but can't be sure from the example.
In R, you don't have to (unless you really want to) explicitly create
separate variables. You can use the
On Wed, 16 Dec 2009, whitaker m. (mw1006) wrote:
Hi,
I am trying to create a set of dummy variables to use within a multiple linear
regression and am unable to find the codes within the manuals.
For example i have:
Price Weight Clarity
IF VVS1VVS2
5
On 12/16/2009 03:58 PM, whitaker m. (mw1006) wrote:
> Hi,
> I am trying to create a set of dummy variables to use within a multiple
> linear regression and am unable to find the codes within the manuals.
>
> For example i have:
> Price Weight Clarity
> IF
5 matches
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