Indexing commands in xts

Case Study: Analyzing City Time Series Data in R

Lore Dirick

Manager of Data Science Curriculum at Flatiron School

Extracting the index

.index() extracts raw time index

.index(unemployment)

 [1] 189302400 191980800 194486400 197164800 
 [5] 199756800 202435200 205027200 207705600 
 [9] 210384000 212976000 215654400 218246400 
[13] 220924800 223603200 226022400 228700800
[17] 231292800 233971200 236563200 239241600

Weekday observations

.indexwday() gives the weekday of each observation

.indexwday(sports)

 [1] 0 2 3 5 6 0 1 3 4 5 6 0 1 2 3 4 5 6 0 1 2 3 5 6 
[25] 0 1 2 3 4 5 6 0 1 2 3 5 6 0 1 2 3 4 5 6 0 1 2 3 
[49] 4 5 6 0 2 3 4 5 6 0 1 2 3 4 5 6 ...

Select only Sunday games

sunday_games <- which(.indexwday(sports) == 0)

Let's practice!

Case Study: Analyzing City Time Series Data in R