# 9.2 - Summarizing Data – tapply() and aggregate()

9.2 - Summarizing Data – tapply() and aggregate()

In the last video we saw how we could use apply() to extract column or row means (though colMeans() would work for that also). Here we'll explore tapply() and aggregate(), which can be used to apply a function to subsets of the data; for example to extract group means.

 [1] Link ↥ Has Tooltip/Popover Toggleable Visibility