Bar Plot

barplot( frequency ,
          main = "Title of the graph" ,
          xlab = "Label of the horizontal line" ,
          ylab = "Label of the vertical line" ,
          col = "color-name/code" ,
          border = "color-of-the-border" ,
          space = #space ,
          ylim = c(#start, #end ) )

Example 1: Bar plot for hair color

HairColor: blonde, black, brown, silver, red, brown, brown, black, blonde, black

# generate variable HairColor
HairColor <- c("blonde", "black", "brown", "silver", "red", "brown", "brown", "black", "blonde", "black")

# generate the frequency for HairColor because barplot() needs the frequency to plot.
HairColor.freq <- table(HairColor)
HairColor.freq
## HairColor
##  black blonde  brown    red silver 
##      3      2      3      1      1
# generate bar plot using barplot()
barplot(HairColor.freq,
        main = "Bar Graph of Hair Colors",
        xlab = "Different Hair Colors",
        ylab = "Number of Students",
        ylim = c(0, 4),
        col = "lightblue",
        border = "tomato2",
        space = 0.8)

Histogram

hist( data/variable/vector ,
      main = "Title of the graph" ,
      xlab = "Label of the horizontal line" ,
      ylab = "Label of the vertical line" ,
      col = "color-name/code" ,
      border = "color-of-the-border" ,
      ylim = c(#start, #end ) )

Score1: 18.5, 19.5, 20, 22, 18.5, 17, 16, 18, 11.5, 10.5, 20, 22.5, 16.5, 13, 11.5, 19, 22, 22, 21, 19.5, 12.5, 21

# generate variable
Score1 <- c( 18.5, 19.5, 20, 22, 18.5, 17, 16, 18, 11.5, 10.5, 20, 22.5, 16.5, 13, 11.5, 19, 22, 22, 21, 19.5, 12.5, 21)

# histogram
hist(Score1,
     main = "Histogram of Exam 1 Score Before Extra Credit",
     ylab = "Number of Students",
     xlab = " Exam Scores",
     ylim = c(0,9),
     col = "steelblue",
     border = "khaki")

Score2: 20.5, 22.5, 21.5, 24,21, 20, 18, 20.5, 14.5, 13, 22.5, 25.5, 19, 14, 11.5, 21, 24.5, 24.5, 23.5, 22.5, 14.5, 22