dplyr

Portal Data Manipulation


Download a copy of the Portal Teaching Database surveys table and load it into R using read.csv().

  1. Use select() to create a new data frame with just the year, month, day, and species_id columns in that order.
  2. Use mutate(), select(), and na.omit() to create a new data frame with the year, species_id, and weight in kilograms of each individual, with no null weights.
  3. Use the filter() function to get all of the rows in the data frame for the species ID SH.
  4. Use the group_by() and summarize() functions to get a count of the number of individuals in each species ID.
  5. Use the group_by() and summarize() functions to get a count of the number of individuals in each species ID in each year.
  6. Use the filter(), group_by(), and summarize() functions to get the mean mass of species DO in each year.