boxplot

Generating two sets of Poisson samples

set.seed(100)
data1 <- rpois(1000, lambda = 2)
set.seed(100)
data2 <- rpois(1000, lambda = 10)

Combining it as a data frame

df <- data.frame(seq1 = data1, seq2 = data2)
rownames(df) <- paste(rep('s',1000), 1:1000,sep = '_')
head(df)

##     seq1 seq2
## s_1    1    8
## s_2    1   10
## s_3    2    9
## s_4    0   12
## s_5    2   10
## s_6    2   11

Generating the boxplot

boxplot(df$seq1, df$seq2)

Adding the lable for X and Y axis

Change the direction of coordiante at Y-axis

boxplot(df$seq1, df$seq2, ylab = 'Reads_count', las = 1,
        names = c('s1', 's2'))

Adding the color for each box, removing the border of the box

boxplot(df$seq1, df$seq2, ylab = 'Reads_count', las = 1,
        names = c('s1', 's2'), col = c('red', 'navy'), ##adding the color
        boxlty = c(0,0),## removing the border of box
        medcol = c('white', 'white')
        )

using ggplot2 for boxplot

library(ggplot2)   #loding  the package 
data(airquality)   #loading the available data
head(airquality)

##   Ozone Solar.R Wind Temp Month Day
## 1    41     190  7.4   67     5   1
## 2    36     118  8.0   72     5   2
## 3    12     149 12.6   74     5   3
## 4    18     313 11.5   62     5   4
## 5    NA      NA 14.3   56     5   5
## 6    28      NA 14.9   66     5   6

aq <- airquality[ !is.na(airquality$Ozone) ,] #removing the missing data for Ozone variable
##draw the boxplot from ggplot2
aq$Month <- as.factor(aq$Month)
p10 <- ggplot(aq, aes(x = Month, y = Ozone)) + 
       geom_boxplot()
p10

##adding the color for each box
p10 <- ggplot(aq, aes(x = Month, y = Ozone)) + 
       geom_boxplot(fill = c('red','gold', 'navy', 'forestgreen', 'purple')) +
       scale_y_continuous(name = 'Mean ozone in parts per billion', ## add the y asis name
                          breaks = seq(0,175,25), # the points at which tick-marks are to be drawn
                          limits = c(0,175))    #the minmum and maxmum of y-axis
p10

using traditional plot

boxplot(aq$Ozone[aq$Month == 5],
        aq$Ozone[aq$Month == 6],
        aq$Ozone[aq$Month == 7],
        aq$Ozone[aq$Month == 8],
        aq$Ozone[aq$Month == 9],
        col = c('red','gold', 'navy', 'forestgreen', 'purple'),
        medcol = rep('white', 5),whisklty = 1,
        boxlty = rep(0,5), names = c('May', 'Jun', 'July', 'Aug', 'Sep'),
        ylab   = 'Mean ozone in parts per billion',
        las = 1)