Lines that intersect are without parallel

Programming with dplyr

Dr. Chester Ismay

Educator, Data Scientist, and R/Python Consultant

Set theory clauses

Compare and combine data from two sources
dplyr has several functions to perform set theory clauses on tibbles

Venn diagrams for set theory

Intersect Venn

Union Venn

Union All Venn

Setdiff Venn

intersect diagram

Uruguay tibbles

uruguay_imf

# A tibble: 9 x 4
  iso   country  year consumer_price_index
  <chr> <chr>   <int>                <dbl>
1 URY   Uruguay  2011                 105.
2 URY   Uruguay  2012                 114.
3 URY   Uruguay  2013                 123.
4 URY   Uruguay  2014                 134.
5 URY   Uruguay  2015                 146.
6 URY   Uruguay  2016                 160.
7 URY   Uruguay  2017                 170.
8 URY   Uruguay  2018                 183.
9 URY   Uruguay  2019                 197.

uruguay_wb

# A tibble: 4 x 4
  iso   country  year perc_rural_pop
  <chr> <chr>   <dbl>          <dbl>
1 URY   Uruguay  2013           5.16
2 URY   Uruguay  2014           5.06
3 URY   Uruguay  2015           4.96
4 URY   Uruguay  2016           4.86

Trying out intersect()

intersect(uruguay_imf, uruguay_wb)

Error: not compatible: 
not compatible: 
- Cols in y but not x: `perc_rural_pop`.
- Cols in x but not y: `consumer_price_index`.

intersect(uruguay_imf$year, uruguay_wb$year)

[1] 2013 2014 2015 2016

Difference between intersect() and a join

intersect() looks for rows in common
inner_join() looks for individual key entries matching

This is an important distinction.

Let's practice!

Programming with dplyr