Wees vruchtbaar met dplyr

Programmeren met dplyr

Dr. Chester Ismay

Educator, Data Scientist, and R/Python Consultant

Cursusvereisten

Data joinen met dplyr
Introductie tot functies schrijven in R

Cursusoverzicht

Hoofdstuk 1

dplyr-pipelines opfrissen
Kolommen kiezen op basis van patronen

Hoofdstuk 2

Kolommen in je data verplaatsen
Transformaties over meerdere kolommen uitvoeren

Hoofdstuk 3

Kennis van dplyr-joins verdiepen
Zet-theorieclausules gebruiken om met meerdere databronnen te programmeren

Hoofdstuk 4

Functies maken om dplyr- en ggplot2-code te bundelen
Het rlang-pakket gebruiken om tidy evaluation te begrijpen

De tibble world_bank_data

country	region	year	infant_mortality_rate	fertility_rate	perc_rural_pop
Saudi Arabia	Western Asia	2013	13.3	2.64	17.260
Greece	Southern Europe	2014	3.7	1.54	22.298
Latvia	Northern Europe	2014	7.2	1.62	32.048
Romania	Eastern Europe	2014	10.1	1.43	46.100
Netherlands	Western Europe	2015	3.2	1.78	9.827

Kolommen van world_bank_data

names(world_bank_data)

 [1] "iso"                   "country"               "continent"            
 [4] "region"                "year"                  "infant_mortality_rate"
 [7] "fertility_rate"        "perc_electric_access"  "perc_college_complete"
[10] "perc_cvd_crd_70"       "unemployment_rate"     "perc_rural_pop"

Selecteer enkele kolommen uit world_bank_data

world_bank_data %>%
    select(country, continent, region, year, perc_rural_pop, perc_college_complete)

# A tibble: 300 x 6
   country      continent region           year perc_rural_pop perc_college_complete
   <chr>        <fct>     <fct>           <dbl>          <dbl>                 <dbl>
 1 Portugal     Europe    Southern Europe  2000          45.6                   7.26
 2 Armenia      Asia      Western Asia     2001          35.6                  20.4 
 3 Bulgaria     Europe    Eastern Europe   2001          30.8                  18.0 
 4 Portugal     Europe    Southern Europe  2001          45.0                   7.57
 5 Qatar        Asia      Western Asia     2004           2.91                 20.9 
 6 Saudi Arabia Asia      Western Asia     2004          19.2                  14.9 
 7 Pakistan     Asia      Southern Asia    2005          66.0                   3.92
# ... with 293 more rows

Rijen filteren op continentwaarden

continents_vector <- c("Africa", "Asia")

asia_africa_results <- world_bank_data %>%
    select(country, continent, region, year, perc_rural_pop, perc_college_complete) %>%
    filter(continent %in% continents_vector)

Resultaten van rijfilter

asia_africa_results

# A tibble: 111 x 6
   country      continent region              year perc_rural_pop perc_college_complete
   <chr>        <fct>     <fct>              <dbl>          <dbl>                 <dbl>
 1 Armenia      Asia      Western Asia        2001          35.6                  20.4 
 2 Qatar        Asia      Western Asia        2004           2.91                 20.9 
 3 Saudi Arabia Asia      Western Asia        2004          19.2                  14.9 
 4 Pakistan     Asia      Southern Asia       2005          66.0                   3.92
 5 Nigeria      Africa    Western Africa      2006          60.1                   9.04
 6 Pakistan     Asia      Southern Asia       2006          65.8                   6.30
 7 Singapore    Asia      South-Eastern Asia  2006           0                    19.6 
 8 Azerbaijan   Asia      Western Asia        2007          47.2                  14.9 
 9 Qatar        Asia      Western Asia        2007           2.08                 25.1 
10 Singapore    Asia      South-Eastern Asia  2007           0                    20.1 
# ... with 101 more rows

Nieuwe kolom muteren

asia_africa_results <- asia_africa_results %>%
    mutate(perc_urban_pop = 100 - perc_rural_pop)

Resultaten van mutate

# A tibble: 111 x 7
   country      continent region              year perc_rural_pop perc_college_complete perc_urban_pop
   <chr>        <fct>     <fct>              <dbl>          <dbl>                 <dbl>          <dbl>
 1 Armenia      Asia      Western Asia        2001          35.6                  20.4            64.4
 2 Qatar        Asia      Western Asia        2004           2.91                 20.9            97.1
 3 Saudi Arabia Asia      Western Asia        2004          19.2                  14.9            80.8
 4 Pakistan     Asia      Southern Asia       2005          66.0                   3.92           34.0
 5 Nigeria      Africa    Western Africa      2006          60.1                   9.04           39.9
 6 Pakistan     Asia      Southern Asia       2006          65.8                   6.30           34.2
 7 Singapore    Asia      South-Eastern Asia  2006           0                    19.6           100  
 8 Azerbaijan   Asia      Western Asia        2007          47.2                  14.9            52.8
 9 Qatar        Asia      Western Asia        2007           2.08                 25.1            97.9
10 Singapore    Asia      South-Eastern Asia  2007           0                    20.1           100  
# ... with 101 more rows

Analyseer stedelijk percentage per regio

asia_africa_results %>%

    group_by(region) %>%

    summarize(
      mean_urban = mean(perc_urban_pop)
    )

# A tibble: 9 x 2
  region             mean_urban
  <fct>                   <dbl>
1 Central Asia             49.2
2 Eastern Africa           19.5
3 Eastern Asia             74.2
4 Middle Africa            42.4
5 South-Eastern Asia       79.8
6 Southern Africa          64.8
7 Southern Asia            40.0
8 Western Africa           39.6
9 Western Asia             78.9

Laten we oefenen!

Programmeren met dplyr