Enter
the data into R using the c(…) command or load the
data into R using read.csv. To run ANOVA in R, the data must be in two columns
with one column containing the factor or treatment and the other column
containing the value of the response variable.
Suppose
we need to enter the data into R. Proceed as follows:
cojet <- c(15.4,12.9,17.2,16.6,19.3)
silistor <- c(17.2,14.3,17.6,21.6,17.5)
cimara <- c(5.5,7.7,12.2,11.4,16.4)
ceramic <- c(11,12.4,13.5,8.9,8.1)ANOVA_data <- data.frame('Outcome' = c(cojet, silistor, cimara, ceramic), 'Treatment' = as.factor(rep(c('Cojet', 'Silistor', 'Cimara', 'Ceramic Repair'), each = 5)))
print(ANOVA_data)
## Outcome Treatment## 1 15.4 Cojet## 2 12.9 Cojet## 3 17.2 Cojet## 4 16.6 Cojet## 5 19.3 Cojet## 6 17.2 Silistor## 7 14.3 Silistor## 8 17.6 Silistor## 9 21.6 Silistor## 10 17.5 Silistor## 11 5.5 Cimara## 12 7.7 Cimara## 13 12.2 Cimara## 14 11.4 Cimara## 15 16.4 Cimara## 16 11.0 Ceramic Repair## 17 12.4 Ceramic Repair## 18 13.5 Ceramic Repair## 19 8.9 Ceramic Repair## 20 8.1 Ceramic RepairNow
we run a one-way ANOVA.
summary(aov(Outcome~Treatment,data=ANOVA_data))## Df Sum Sq Mean Sq F value Pr(>F) ## Treatment 3 200.0 66.66 7.545 0.00229 **## Residuals 16 141.4 8.84 ## ---## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1The
P-value for the one-way ANOVA is 0.00229.
Install
the Mosaic package, if necessary, using the command
install.packages(“mosaic”)
Now
use the aov() command from Mosaic.
library(mosaic)summary(aov(Outcome~Treatment,data=ANOVA_data))## Df Sum Sq Mean Sq F value Pr(>F) ## Treatment 3 200.0 66.66 7.545 0.00229 **## Residuals 16 141.4 8.84 ## ---## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1The
P-value for the one-way ANOVA is 0.00229.