[BioC] model.matrix()

[Gordon K Smyth]

Dear Yisong,

Actually you mean "~-1+" rather than "~1+".

Both "-1" and "0" have the same meaning in a formula in R.  There is no 
difference.  See

   help("formula")

Best wishes
Gordon

> Date: Mon, 28 Jul 2008 18:48:36 -0700
> From: "Yisong Zhen" <zhenyisong at gmail.com>
> Subject: [BioC] model.matrix()
> To: bioconductor at stat.math.ethz.ch
> Message-ID:
> 	<70d4fa2d0807281848p2655258ev36983347c1e0720 at mail.gmail.com>
> Content-Type: text/plain
>
> Hello list,
>
> I am confused about the model.matrix(). In the limma manual, Page 31, there
> is a design matrix, model.matrix(~1+..). But in the Page 44, the desgin
> matrix is model.matrix(~0+...). What's is the diffirence between  -1 or 0?
> Thanks.
>
> Bests,
>
> Yisong