Program_13

Author

Asha

Write an R program to create multiple dot plots for grouped data, comparing the distributions of variables across different categories, using ggplot2’s position_dodge function.

Step 1: Install and load ggplot2

# install.packages("ggplot2")
library(ggplot2)

Step 2: Load dataset

data(ToothGrowth)
head(ToothGrowth)

   len supp dose
1  4.2   VC  0.5
2 11.5   VC  0.5
3  7.3   VC  0.5
4  5.8   VC  0.5
5  6.4   VC  0.5
6 10.0   VC  0.5

str(ToothGrowth)

'data.frame':   60 obs. of  3 variables:
 $ len : num  4.2 11.5 7.3 5.8 6.4 10 11.2 11.2 5.2 7 ...
 $ supp: Factor w/ 2 levels "OJ","VC": 2 2 2 2 2 2 2 2 2 2 ...
 $ dose: num  0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 ...

Step 3: Create dot plot with grouping

ggplot(ToothGrowth, aes(x = factor(dose), y = len, color = supp)) +
  geom_dotplot(
    binaxis = "y",
    stackdir = "center",
    position = position_dodge(width = 0.7),
    binpositions = "all",
    dotsize = 1.0
  ) +
  labs(
    title = "Tooth Growth by Dose and Supplement Type",
    x = "Dose",
    y = "Tooth Length",
    color = "Supplement"
  ) +
  theme_minimal()

Bin width defaults to 1/30 of the range of the data. Pick better value with
`binwidth`.