Dear colleagues,
How can I do to "relevel" the intercept?
I need that the treatment "Db" be the intercept, and have p-values for the
comparisons with the others treatments.
I used the function "relevel" but it did not work out to have what I want.
Thanks for your help,
Xavier
T1 <- read.table(file.choose(), h=T)
> head(T1)
treatment replicate Time Ebcg
1 CHA0+Db 1 1 9681172
2 CHA0+Db 2 1 5599000
3 CHA0+Db 3 1 10280480
4 CHA0+Db 4 1 1004526
5 CHA0+Db 5 1 12942018
6 CHA0+Db 6 1 7478773
> attach(T1)
> summary(T1)
treatment replicate Time Ebcg
CHA0 :6 Min. :1.000 Min. :1 Min. : 0
CHA0+Db:9 1st Qu.:2.750 1st Qu.:1 1st Qu.: 1000922
Db :9 Median :4.500 Median :1 Median : 4044094
Healthy:9 Mean :4.625 Mean :1 Mean : 5699717
PCL :6 3rd Qu.:6.250 3rd Qu.:1 3rd Qu.: 7785782
PCL+Db :9 Max. :9.000 Max. :1 Max. :24736254
> hist(Ebcg)
> treatment<-relevel(treatment,ref="Db")
> mT1<-lm(sqrt(Ebcg)~treatment,data=T1)
> summary(mT1)
Call:
lm(formula = sqrt(Ebcg) ~ treatment, data = T1)
Residuals:
Min 1Q Median 3Q Max
-1748.12 -540.19 0.97 545.14 1949.22
Coefficients:
Estimate Std. Error t value
Pr(>|t|)
(Intercept) 532.5 384.4 1.385
0.173296
treatmentCHA0+Db 2048.5 496.3 4.128 0.000170 ***
treatmentDb 2491.9 496.3 5.021 9.93e-06
***
treatmentHealthy 1215.6 496.3 2.450 0.018552 *
treatmentPCL 120.4 543.6 0.221 0.825816
treatmentPCL+Db 2098.9 496.3 4.229 0.000124 ***
---
Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
Residual standard error: 941.6 on 42 degrees of freedom
Multiple R-squared: 0.5206, Adjusted R-squared: 0.4635
F-statistic: 9.121 on 5 and 42 DF, p-value: 6.227e-06
Xavier Chiriboga M.
PhD Candidate
Fundamental and Applied Research in Chemical Ecology Lab.
Institute of Biology
University of Neuchatel
Website: https://www.unine.ch/farce/home/membres/xavier-chiriboga.html
[[alternative HTML version deleted]]
______________________________________________
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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.
