Hi All,
I am trying to fit a linear regression between the tool speed and the tool
type ( type A, Type B , Type C) where the response is the tool speed and the
regressor is the tool type.
I introduced two dummy variables X1 and X2 as follows
X1 X2
Tool A 0 0
Tool B 0 1
Tool C 1 0
Model<-Lm (y~X1+X2)
My question is on the residual plot, it looks like three cluster because I
have three tool types. Is such a plot is ok with the constant variance
assumption and normality (below is a link for the plot)?I have never seen
such a plot of the residuals
http://www.nabble.com/file/p22972254/question.JPG question.JPG
--
View this message in context:
http://www.nabble.com/residuals-tp22972254p22972254.html
Sent from the R help mailing list archive at Nabble.com.
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
