Select elements in objects
This exercise focuses on extracting different elements from objects in R. Your workspace environment includes the objects created previously: two numeric vectors numvec1
and numvec2
, one character vector charvec
, a matrix nummtx
, and a dataframe dataframe
. Type the name of each object in the console to view them again if you wish. The dplyr
package is also loaded.
You will get experience selecting elements from each type of object (vector, matrix, and dataframe).
This exercise is part of the course
R For SAS Users
Exercise instructions
- Select the 2nd element in vector
charvec
- Select the 2nd column of matrix
nummtx
- Pull column
numvec1
from dataframedataframe
assign it to an object namedid
- Pull column
charvec
from dataframedataframe
determine the class ofcharvec
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# Select the 2nd element in vector charvec
charvec[___]
# Select the 2nd column of matrix nummtx
nummtx[___]
# Pull column numvec1 from dataframe assign it to id
___ <- ___ %>%
___
# Pull column charvec from dataframe and determine the class of charvec
___ %>%
___ %>%
___