Question

The famous data set iris which gives the measurements in centimeters of the variables sepal length and width and petal length and width, respectively, for 50 flowers from each of 3 species of iris is available in R. Type iris directly to see what it looks like.

(a) Selecting the observations (rows) whose Species are versicolor.

(b) Selecting the observations whose Speices are either versicolor or virginica.

(c) Selecting the observations whose Sepal.Width are greater than 2.9 but less than 3.5.

(d) Combine the data frames you got in part (a) and part (c) to one data frame.

(e) You may have some duplicated observations in the data frame you obtained in part (d). Use the command ?unique to learn the usage of the function unique and then utilize it to remove duplicated rows from the data frame you obtained in part (d).

Answer 1

R CODE:

iris

# Q1.

iris_a = iris[iris$Species == "versicolor", ]
iris_a

# Q2.

iris_b = iris[iris$Species == "versicolor" | iris$Species == "virginica" , ]
iris_b

# Q3.

iris_c = iris[iris$Sepal.Width > 2.9 & iris$Sepal.Width < 3.5 , ]
iris_c

# Q4.

iris_d = rbind(iris_a, iris_c)
iris_d

# Q5.

iris_e = unique(iris_d)
iris_e

# Result related
> nrow(iris_d)
[1] 118
> nrow(iris_e)
[1] 102