Portal Species Time-Series (Functions)

If surveys.csv, species.csv, and plots.csv are not available in your workspace download them:

Load them into R using read.csv().

Do the following (no output is expected for (1) or (2)):

1. Combine the surveys and species tables into a single data frame
2. Write a function that
   • Takes three arguments - a data frame (the combined table created in (1)), a genus name, and a species name
   • Uses dplyr to produce a data frame with a two columns: year and count, where count is the number of individuals (i.e., the number of rows) for the species indicated by genus and species in that year
   • Returns the resulting data frame
3. Use your function to get the time-series for genus = "Dipodomys" and species = "merriami" and then make a graph of this time-series using ggplot that has year on the x axis, count on the y axis, and displays the data as points.
4. Use your function to get the time-series for genus = "Chaetodipus" and species = "penicillatus" and then make a graph of this time-series using ggplot that has year on the x axis, count on the y axis, and displays the data as blue points (with size = 1) connected by blue lines (with size = 2). Change the x axis label to Year and the y axis label to Number of Individuals

Expected outputs for Portal Species Time-Series: 1 2