An R package for ps209 students
Provides functions useful for students of UCLA Political Science 209 in Winter 2019. At the moment, the package
provides only one function, step_through_pipes. The purpose of step_through_pipes is to provide a convenient way to
see the head of the result of each intermediate step in a block of piped expressions as might be constructed when manipulating
data with dplyr.
For example,
library(tidyverse)
thin_character_dat <- step_through_pipes({
starwars %>%
mutate(bmi=mass/((height/100)^2)) %>%
select(name:mass, bmi) %>%
filter(bmi<22) %>%
gather(feature, value)
})
results in
Stepping through pipes:
===========================================
. %>% mutate(bmi = mass/((height/100)^2))
===========================================
# A tibble: 6 x 14
name height mass hair_color skin_color eye_color birth_year
<chr> <int> <dbl> <chr> <chr> <chr> <dbl>
1 Luke… 172 77 blond fair blue 19
2 C-3PO 167 75 NA gold yellow 112
3 R2-D2 96 32 NA white, bl… red 33
4 Dart… 202 136 none white yellow 41.9
5 Leia… 150 49 brown light brown 19
6 Owen… 178 120 brown, gr… light blue 52
# … with 7 more variables: gender <chr>, homeworld <chr>,
# species <chr>, films <list>, vehicles <list>,
# starships <list>, bmi <dbl>
===============================
. %>% select(name:mass, bmi)
===============================
# A tibble: 6 x 4
name height mass bmi
<chr> <int> <dbl> <dbl>
1 Luke Skywalker 172 77 26.0
2 C-3PO 167 75 26.9
3 R2-D2 96 32 34.7
4 Darth Vader 202 136 33.3
5 Leia Organa 150 49 21.8
6 Owen Lars 178 120 37.9
=========================
. %>% filter(bmi < 22)
=========================
# A tibble: 6 x 4
name height mass bmi
<chr> <int> <dbl> <dbl>
1 Leia Organa 150 49 21.8
2 Chewbacca 228 112 21.5
3 Jar Jar Binks 196 66 17.2
4 Roos Tarpals 224 82 16.3
5 Ayla Secura 178 55 17.4
6 Ki-Adi-Mundi 198 82 20.9
======================================
. %>% gather(feature, value, -name)
======================================
# A tibble: 6 x 3
name feature value
<chr> <chr> <dbl>
1 Leia Organa height 150
2 Chewbacca height 228
3 Jar Jar Binks height 196
4 Roos Tarpals height 224
5 Ayla Secura height 178
6 Ki-Adi-Mundi height 198
==========----==================
. %>% arrange(name, feature)
================================
# A tibble: 6 x 3
name feature value
<chr> <chr> <dbl>
1 Adi Gallia bmi 14.8
2 Adi Gallia height 184
3 Adi Gallia mass 50
4 Ayla Secura bmi 17.4
5 Ayla Secura height 178
6 Ayla Secura mass 55
Pipes completed!