CITS4009 Introduction to Data Science Laboratory Sheet 1

CITS4009 Introduction to Data Science

Learning basics of R

Here is an R manual

• learn to use the help in R. For example, help("subset") will show you the options for using the subset function.
• Create the vectors:
  • (1,2,3,...,19,20)
  • (20,19, ...., 2,1)
  • (1,2,3,...,19,20,19,18,..,2,1)
  • (4,6,3) and assign it to the name tmp
• Look at the help for the function rep and do the following exercises using the tmp vector:
  • (4,6,3,4,6,3,...,4,6,3) where there are 10 occurrences of 4.
  • (4,6,3,4,6,3,...,4,6,3,4) where there are 11 occurrences of 4, 10 occurrences of 6 and 10 occurrences of 3.
  • (4,4,...,4,6,6,...,6, 3,3,...,3) where there are 10 occurrences of 4, 20 occurrences of 6 and 30 occurrences of 3.
• Use the function paste to create the following character vectors of length 30:
  • ("label 1", "label 2", ...., "label 30")
    Note that there is a single space between label and the number folloing
  • ("fn1", "fn2", ..., "fn30")
    In this case there is no space between fn and the number following.
• Learn how to set the working directory by using the function setwd
• The following exercises are on reading a file and analysing it:
  • Save this csv (comma separated values) file in your working directory. Read the file using the read.csv function into a data frame called rw.
  • Create a vector by choosing the values for only the fixed acidity column.
  • Sort the values in the vector that you have created in the previous step.
  • Create a vector where fixed acidity is greater than or equal to 7,
  • Create a table with only the columns residual sugar and density.

Amitava Datta
August 2017

School of Computer Science & Software Engineering The University of Western Australia Crawley, Western Australia, 6009. Phone: +61 8 9380 2716 - Fax: +61 8 9380 1089. CRICOS provider code 00126G