Exercise

Plotting a time series object

It is often very useful to plot data we are analyzing, as is the case when conducting time series analysis. If the dataset under study is of the ts class, then the plot() function has methods that automatically incorporate time index information into a figure.

Let's consider the eu_stocks dataset (available in R by default as EuStockMarkets). This dataset contains daily closing prices of major European stock indices from 1991-1998, specifically, from Germany (DAX), Switzerland (SMI), France (CAC), and the UK (FTSE). The data were observed when the markets were open, so there are no observations on weekends and holidays. We will proceed with the approximation that this dataset has evenly spaced observations and is a four dimensional time series.

To conclude this chapter, this exercise asks you to apply several of the functions you've already learned to this new dataset.

Instructions

100 XP
  • Use is.ts() to check whether eu_stocks is a ts object.
  • View the start, end, and frequency of eu_stocks using the start(), end(), and frequency() functions, respectively.
  • Generate a simple plot of your eu_stocks data using the plot() command.
  • Generate a more complex time series plot of your eu_stocks data using the ts.plot() command. Input the eu_stocks dataset into the pre-written code, but leave the other arguments as they are.
  • Use the pre-written code to add a legend to your time series plot.