Dplyr-shrub-volume-aggregation-R.md

layout	topic	title	language
exercise	dplyr	Shrub Volume Aggregation	R

This is a follow-up to [Shrub Volume Data Basics]({{ site.baseurl }}/exercises/Dplyr-shrub-volume-data-basics-R).

Dr. Morales wants some summary data of the plants at her sites and for her experiments. If the file [shrub-volume-data.csv]({{ site.baseurl }}/data/shrub-volume-data.csv) is not already in your work space download it.

This code calculates the average height of a plant at each site:

shrub_dims <- read.csv('shrub-volume-data.csv')
by_site <- group_by(shrub_dims, site)
avg_height <- summarize(by_site, avg_height = mean(height))

1. Modify the code to calculate and print the average height of a plant in each experiment.
2. Add a line of code to use max() to determine the maximum height of a plant at each site.