From: Wuming Gong <wuming.gong_at_gmail.com>

Date: Sat 21 May 2005 - 03:54:27 EST

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Sat May 21 03:58:44 2005

Date: Sat 21 May 2005 - 03:54:27 EST

You may fit the model using lm() directly - R will set up a coding for qualitative predictor automatically (taking experiments as qualitative predictor).

**HTH
**
Wuming

On 5/18/05, ©sªY <xmeng@capitalbio.com> wrote:

> Hello sir:

*> Here's a question on covariance analysis which needs your help.
**> There're 3 experiments,and x refers to control while y refers to experimental result.
**> The purpose is to compare the "y" values across the 3 experiments.
**>
**> experiment_1:
**> x:0.1 0.2 0.3 0.4 0.5
**> y:0.5 0.6 0.6 0.7 0.9
**>
**> experiment_2:
**> x:1 2 3 4 5
**> y:3 4 6.5 7.5 11
**>
**> experiment_3:
**> x:10 20 30 40 50
**> y:18 35 75 90 98
**>
**> Apparently,the control("x") isn't at the similar level so that we can't compare the "y" directly through ANOVA.
**> We must normalize "y" via "x" in order to eliminate the influence of different level of "x".
**> The method of normalize I can get is "covariance analysis",since "x" is the covariant of y.
**>
**> My question is:
**> How to perform "covariance analysis" by using R?
**> After this normalization,we can get the according "normalized y" of every "original y".
**>
**> All in all,the "normalized y" of every "original y" is what I want indeed.
**>
**>
**> Thanks a lot!
**>
**> My best regards!
**>
**>
**>
**>
**>
**>
**> ------------------------------
**> *******************************************
**> Xin Meng
**> Capitalbio Corporation
**> National Engineering Research Center
**> for Beijing Biochip Technology
**> Microarray and Bioinformatics Dept.
**> Research Engineer
**> Tel: +86-10-80715888/80726868-6364/6333
**> Fax: +86-10-80726790
**> Email¡Gxmeng@capitalbio.com
**> Address:18 Life Science Parkway,
**> Changping District, Beijing 102206, China
**>
**> ______________________________________________
**> R-help@stat.math.ethz.ch mailing list
**> https://stat.ethz.ch/mailman/listinfo/r-help
**> PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
**>
*

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Sat May 21 03:58:44 2005

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