One way ANOVA in R

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Revision as of 23:41, 11 November 2015 by Teklab (talk | contribs)

The one way analysis of variance is used to test if three or more means are equal. One way ANOVA is an extension of two independent samples t-test.

using R

  • Open the R console
  • Change the working directory to the directory where your file is"
   setwd('C:/Users/yourfolder')
  • Read the file: E.g the file used here is smaple.csv. The file has three groups with the following format
Header 1 Header 2 Header 3
a b c
d e f
  • Read the file and name it (e.g metab)
   metab <- read.csv ("sample.csv, header= T)
  • confirm the file is imported. When you call for metab and press enter you should see the table
  • make box plot
   boxplot(metab)
  • Then use the following command to conduct one way anova and Tukey's test
   smetab <- stack(metab) 
names(smetab) <- c("length", "group")
smetab
av1<-aov(length ~ group, data=smetab)
summary(av1)
tk<- TukeyHSD(av1)
tk