Exercise 1

library(readr)
library(dplyr)
## 
## Attaching package: 'dplyr'
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
library(purrr)

data_path <- "C:/Users/tsander/OneDrive - Rehab United Inc/R/Module 6 Data/data"

# Get all Month-XX.csv files from that folder
files <- list.files(path = data_path,
                    pattern = "(?i)^Month-\\d{1,2}\\.csv$", # matches Month-1.csv or Month-01.csv
                    full.names = TRUE)

# Read and combine
all_data <- map_dfr(files, ~ suppressMessages(read_csv(.x)))

# Confirm size
dim(all_data)  # should be 698159 rows, 10 columns
## [1] 698159     10
glimpse(all_data)
## Rows: 698,159
## Columns: 10
## $ Account_ID            <dbl> 5, 16, 28, 40, 62, 64, 69, 69, 70, 79, 88, 90, 9…
## $ Transaction_Timestamp <dttm> 2009-01-08 00:16:41, 2009-01-20 22:40:08, 2009-…
## $ Factor_A              <dbl> 2, 2, 2, 2, 2, 7, 2, 2, 2, 7, 8, 10, 10, 2, 2, 2…
## $ Factor_B              <dbl> 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 18, 6, 6, 6, 6, 6,…
## $ Factor_C              <chr> "VI", "VI", "VI", "VI", "VI", "MC", "VI", "VI", …
## $ Factor_D              <dbl> 20, 20, 21, 20, 20, 20, 20, 20, 20, 20, 20, 20, …
## $ Factor_E              <chr> "A", "H", "NULL", "H", "B", "NULL", "H", "H", "B…
## $ Response              <dbl> 1020, 1020, 1020, 1020, 1020, 1020, 1020, 1020, …
## $ Transaction_Status    <chr> "Approved", "Approved", "Approved", "Approved", …
## $ Month                 <chr> "Jan", "Jan", "Jan", "Jan", "Jan", "Jan", "Jan",…

Exercise 2

map(all_data, class)
## $Account_ID
## [1] "numeric"
## 
## $Transaction_Timestamp
## [1] "POSIXct" "POSIXt" 
## 
## $Factor_A
## [1] "numeric"
## 
## $Factor_B
## [1] "numeric"
## 
## $Factor_C
## [1] "character"
## 
## $Factor_D
## [1] "numeric"
## 
## $Factor_E
## [1] "character"
## 
## $Response
## [1] "numeric"
## 
## $Transaction_Status
## [1] "character"
## 
## $Month
## [1] "character"

Exercise 3

map_int(all_data, ~ length(unique(.x)))
##            Account_ID Transaction_Timestamp              Factor_A 
##                475413                686538                     7 
##              Factor_B              Factor_C              Factor_D 
##                     6                     4                    15 
##              Factor_E              Response    Transaction_Status 
##                    63                    42                     2 
##                 Month 
##                    11

Exercise 4

# Mutate anything that is 26 to 25
all_data <- all_data %>%
  mutate(Factor_D = if_else(Factor_D == 26, 25, Factor_D))

# Count unique values
n_distinct(all_data$Factor_D)
## [1] 14
# Count observations for each level
all_data %>%
  count(Factor_D)
## # A tibble: 14 × 2
##    Factor_D      n
##       <dbl>  <int>
##  1       10   4595
##  2       15   1089
##  3       20 527882
##  4       21  68072
##  5       25  41021
##  6       30   7030
##  7       31    512
##  8       35  25298
##  9       40   2720
## 10       50   3709
## 11       55  15200
## 12       70     54
## 13       85      4
## 14       90    973

After recoding, Factor_D now contains 14 unique values.

Exercise 5

all_data %>%
  summarise(across(starts_with("Factor_"), ~ sum(. == "NULL", na.rm = TRUE)))
## # A tibble: 1 × 5
##   Factor_A Factor_B Factor_C Factor_D Factor_E
##      <int>    <int>    <int>    <int>    <int>
## 1        0        0        0        0   208622
# keep only rows where ALL Factor_ columns are not "NULL"
all_data <- all_data %>%
  filter_at(vars(starts_with("Factor_")), all_vars(. != "NULL"))

nrow(all_data) 
## [1] 489537

After filtering out rows containing the string “NULL” in any Factor_ column, the dataset has 489537 rows.

Exercise 6

all_data <- all_data %>%
  mutate_at(vars(-Transaction_Timestamp), as.factor) %>%
  mutate(Month = factor(Month,
                        levels = c("Jan","Feb","Mar","Apr","May","Jun",
                                   "Jul","Aug","Sep","Oct","Nov","Dec"),
                        ordered = TRUE))

# make sure all features are changed to factors
glimpse(df)
## function (x, df1, df2, ncp, log = FALSE)
# make sure the Month variable is an ordered factor
levels(all_data$Month)
##  [1] "Jan" "Feb" "Mar" "Apr" "May" "Jun" "Jul" "Aug" "Sep" "Oct" "Nov" "Dec"

Exercise 7

all_data %>%
  summarize_if(is.factor, n_distinct)
## # A tibble: 1 × 9
##   Account_ID Factor_A Factor_B Factor_C Factor_D Factor_E Response
##        <int>    <int>    <int>    <int>    <int>    <int>    <int>
## 1     324174        2        3        2       12       62       30
## # ℹ 2 more variables: Transaction_Status <int>, Month <int>
all_data %>%
  group_by(Transaction_Status) %>%
  summarize_if(is.factor, n_distinct)
## # A tibble: 2 × 9
##   Transaction_Status Account_ID Factor_A Factor_B Factor_C Factor_D Factor_E
##   <fct>                   <int>    <int>    <int>    <int>    <int>    <int>
## 1 Approved               316172        2        3        2       11       59
## 2 Declined                14066        2        3        2       11       57
## # ℹ 2 more variables: Response <int>, Month <int>

When grouping by Transaction_Status, most variables show an equal number of unique values across the Approved and Declined transactions. The only exceptions are:

This indicates near-equal representation across variables overall, with some imbalance in these two cases.

Exercise 8

convert_to_qtr <- function(month_vec) {
  case_when(
    month_vec %in% c("Jan", "Feb", "Mar") ~ "Q1",
    month_vec %in% c("Apr", "May", "Jun") ~ "Q2",
    month_vec %in% c("Jul", "Aug", "Sep") ~ "Q3",
    month_vec %in% c("Oct", "Nov", "Dec") ~ "Q4",
    TRUE ~ NA_character_
  )
}

# TEST
example_months <- c("Jan", "Mar", "May", "May", "Aug", "Nov", "Nov", "Dec")
convert_to_qtr(example_months)
## [1] "Q1" "Q1" "Q2" "Q2" "Q3" "Q4" "Q4" "Q4"
all_data <- all_data %>%
  mutate(Qtr = convert_to_qtr(Month))

all_data %>%
  count(Qtr)
## # A tibble: 4 × 2
##   Qtr        n
##   <chr>  <int>
## 1 Q1     85588
## 2 Q2    100227
## 3 Q3    161071
## 4 Q4    142651

Exercise 9

library(repurrrsive)

sw_people %>% map_chr(~ .x$name)
##  [1] "Luke Skywalker"        "C-3PO"                 "R2-D2"                
##  [4] "Darth Vader"           "Leia Organa"           "Owen Lars"            
##  [7] "Beru Whitesun lars"    "R5-D4"                 "Biggs Darklighter"    
## [10] "Obi-Wan Kenobi"        "Anakin Skywalker"      "Wilhuff Tarkin"       
## [13] "Chewbacca"             "Han Solo"              "Greedo"               
## [16] "Jabba Desilijic Tiure" "Wedge Antilles"        "Jek Tono Porkins"     
## [19] "Yoda"                  "Palpatine"             "Boba Fett"            
## [22] "IG-88"                 "Bossk"                 "Lando Calrissian"     
## [25] "Lobot"                 "Ackbar"                "Mon Mothma"           
## [28] "Arvel Crynyd"          "Wicket Systri Warrick" "Nien Nunb"            
## [31] "Qui-Gon Jinn"          "Nute Gunray"           "Finis Valorum"        
## [34] "Jar Jar Binks"         "Roos Tarpals"          "Rugor Nass"           
## [37] "Ric Olié"              "Watto"                 "Sebulba"              
## [40] "Quarsh Panaka"         "Shmi Skywalker"        "Darth Maul"           
## [43] "Bib Fortuna"           "Ayla Secura"           "Dud Bolt"             
## [46] "Gasgano"               "Ben Quadinaros"        "Mace Windu"           
## [49] "Ki-Adi-Mundi"          "Kit Fisto"             "Eeth Koth"            
## [52] "Adi Gallia"            "Saesee Tiin"           "Yarael Poof"          
## [55] "Plo Koon"              "Mas Amedda"            "Gregar Typho"         
## [58] "Cordé"                 "Cliegg Lars"           "Poggle the Lesser"    
## [61] "Luminara Unduli"       "Barriss Offee"         "Dormé"                
## [64] "Dooku"                 "Bail Prestor Organa"   "Jango Fett"           
## [67] "Zam Wesell"            "Dexter Jettster"       "Lama Su"              
## [70] "Taun We"               "Jocasta Nu"            "Ratts Tyerell"        
## [73] "R4-P17"                "Wat Tambor"            "San Hill"             
## [76] "Shaak Ti"              "Grievous"              "Tarfful"              
## [79] "Raymus Antilles"       "Sly Moore"             "Tion Medon"           
## [82] "Finn"                  "Rey"                   "Poe Dameron"          
## [85] "BB8"                   "Captain Phasma"        "Padmé Amidala"

Exercise 10

sw_people %>% map_int(~ length(.x$films))
##  [1] 5 6 7 4 5 3 3 1 1 6 3 2 5 4 1 3 3 1 5 5 3 1 1 2 1 2 1 1 1 1 1 3 1 2 1 1 1 2
## [39] 1 1 2 1 1 3 1 1 1 3 3 3 2 2 2 1 3 2 1 1 1 2 2 1 1 2 2 1 1 1 1 1 1 1 2 1 1 2
## [77] 1 1 2 2 1 1 1 1 1 1 3
top10_films <- tibble(
  name    = sw_people %>% map_chr("name"),
  n_films = sw_people %>% map_int(~ length(.x$films))
) %>%
  arrange(desc(n_films)) %>%   
  slice_head(n = 10)           

top10_films
## # A tibble: 10 × 2
##    name           n_films
##    <chr>            <int>
##  1 R2-D2                7
##  2 C-3PO                6
##  3 Obi-Wan Kenobi       6
##  4 Luke Skywalker       5
##  5 Leia Organa          5
##  6 Chewbacca            5
##  7 Yoda                 5
##  8 Palpatine            5
##  9 Darth Vader          4
## 10 Han Solo             4

Exercise 11

library(tidyverse)
## ── Attaching core tidyverse packages ──────────────────────── tidyverse 2.0.0 ──
## ✔ forcats   1.0.0     ✔ stringr   1.5.2
## ✔ ggplot2   3.5.2     ✔ tibble    3.3.0
## ✔ lubridate 1.9.4     ✔ tidyr     1.3.1
## ── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
## ✖ dplyr::filter() masks stats::filter()
## ✖ dplyr::lag()    masks stats::lag()
## ℹ Use the conflicted package (<http://conflicted.r-lib.org/>) to force all conflicts to become errors
sw_people %>%
  map_chr("name") %>%                     
  set_names(sw_people, nm = .) %>%          
  map_df(~ length(.x$films)) %>%             
  pivot_longer(
    cols = everything(),
    names_to = "Character",
    values_to = "Films"
  ) %>%
  ggplot(aes(Films, reorder(Character, Films))) +
  geom_point()