zoo::yearqtr
Seen most often in financial and business settings, the concept of 'quarters of a year' is important in time series analysis. The zoo
package introduces the yearqtr
class, which stores both the year and quarter components of a date.
In this exercise, you'll work with quarterly sales data, quarterly_data
, and an index of dates of observations, date_index_quarter
, with each observation occurring each quarter of the year (every three months).
The above datasets, as well as the ggplot2
, zoo
, and lubridate
packages are available to you.
This exercise is part of the course
Manipulating Time Series Data in R
Exercise instructions
Create an index,
index_yearqtr
, by converting thedate_index_quarter
vector to theyearqtr
class.Create
quarterly_sales
, azoo
based on the data inquarterly_data
and the index you created,index_yearqtr
.Add the x-axis label
"Quarter"
, the y-axis label"Quarterly Sum ($100k)"
, and the title"Quarterly Sales Report"
.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# Create a year-quarter index
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# Create the quarterly_sales zoo object
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# Autoplot with axis labels and a title
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