library(tidyverse)
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library(correlationfunnel)
## ══ correlationfunnel Tip #2 ════════════════════════════════════════════════════
## Clean your NA's prior to using `binarize()`.
## Missing values and cleaning data are critical to getting great correlations. :)
library(recipes)
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library(tidymodels)
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library(themis)
library(doParallel)
## Loading required package: foreach
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data <- read_csv('https://raw.githubusercontent.com/rfordatascience/tidytuesday/main/data/2020/2020-11-03/ikea.csv')
## New names:
## Rows: 3694 Columns: 14
## ── Column specification
## ──────────────────────────────────────────────────────── Delimiter: "," chr
## (7): name, category, old_price, link, other_colors, short_description, d... dbl
## (6): ...1, item_id, price, depth, height, width lgl (1): sellable_online
## ℹ Use `spec()` to retrieve the full column specification for this data. ℹ
## Specify the column types or set `show_col_types = FALSE` to quiet this message.
## • `` -> `...1`

Issues with data

data_clean <- data %>%
  mutate(
    category = as.factor(category),
    sellable_online = factor(sellable_online, levels = c(FALSE, TRUE), labels = c("No", "Yes")),
    other_colors = as.factor(other_colors),
    designer = as.factor(designer)
  ) %>%
  select(-`...1`, -item_id, -link, -short_description, -old_price, -name)

Explore data

data_clean %>% count(category)
## # A tibble: 17 × 2
##    category                                 n
##    <fct>                                <int>
##  1 Bar furniture                           47
##  2 Beds                                   208
##  3 Bookcases & shelving units             548
##  4 Cabinets & cupboards                   292
##  5 Café furniture                          26
##  6 Chairs                                 481
##  7 Chests of drawers & drawer units       125
##  8 Children's furniture                   124
##  9 Nursery furniture                       97
## 10 Outdoor furniture                      216
## 11 Room dividers                           13
## 12 Sideboards, buffets & console tables    23
## 13 Sofas & armchairs                      428
## 14 Tables & desks                         612
## 15 Trolleys                                28
## 16 TV & media furniture                   190
## 17 Wardrobes                              236
data_clean %>%
  ggplot(aes(category)) +
  geom_bar() +
  coord_flip()

data_clean %>%
  ggplot(aes(category, price)) +
  geom_boxplot() +
  coord_flip()

# step 1: binarizes
data_model <- data_clean %>%
  drop_na(depth, height, width)

# step 2: correlation
data_binarized <- data_model %>%
  binarize()

data_binarized %>% glimpse()
## Rows: 1,899
## Columns: 58
## $ category__Bar_furniture                          <dbl> 1, 1, 1, 1, 1, 1, 1, …
## $ category__Beds                                   <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ `category__Bookcases_&_shelving_units`           <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ `category__Cabinets_&_cupboards`                 <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ category__Chairs                                 <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ `category__Chests_of_drawers_&_drawer_units`     <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ `category__Children's_furniture`                 <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ category__Nursery_furniture                      <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ category__Outdoor_furniture                      <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ `category__Sideboards,_buffets_&_console_tables` <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ `category__Sofas_&_armchairs`                    <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ `category__Tables_&_desks`                       <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ `category__TV_&_media_furniture`                 <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ category__Wardrobes                              <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ `category__-OTHER`                               <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ `price__-Inf_295`                                <dbl> 1, 1, 0, 1, 1, 1, 0, …
## $ price__295_680                                   <dbl> 0, 0, 1, 0, 0, 0, 1, …
## $ price__680_1589                                  <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ price__1589_Inf                                  <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ sellable_online__Yes                             <dbl> 1, 1, 1, 1, 1, 1, 1, …
## $ `sellable_online__-OTHER`                        <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ other_colors__No                                 <dbl> 0, 1, 1, 1, 1, 1, 1, …
## $ other_colors__Yes                                <dbl> 1, 0, 0, 0, 0, 0, 0, …
## $ designer__Andreas_Fredriksson                    <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ designer__Carina_Bengs                           <dbl> 0, 0, 1, 0, 0, 0, 1, …
## $ designer__Carl_Öjerstam                          <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ designer__Ebba_Strandmark                        <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ designer__Ehlén_Johansson                        <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ `designer__Ehlén_Johansson/IKEA_of_Sweden`       <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ designer__Eva_Lilja_Löwenhielm                   <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ designer__Francis_Cayouette                      <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ designer__Gillis_Lundgren                        <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ designer__Henrik_Preutz                          <dbl> 1, 0, 0, 0, 0, 0, 0, …
## $ designer__IKEA_of_Sweden                         <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ `designer__IKEA_of_Sweden/Ehlén_Johansson`       <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ `designer__IKEA_of_Sweden/Jon_Karlsson`          <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ designer__Johan_Kroon                            <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ designer__Jon_Karlsson                           <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ `designer__Jon_Karlsson/IKEA_of_Sweden`          <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ `designer__K_Hagberg/M_Hagberg`                  <dbl> 0, 0, 0, 1, 1, 1, 0, …
## $ designer__Mia_Lagerman                           <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ designer__Nike_Karlsson                          <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ designer__Ola_Wihlborg                           <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ designer__Studio_Copenhagen                      <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ designer__Tord_Björklund                         <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ `designer__-OTHER`                               <dbl> 0, 1, 0, 0, 0, 0, 0, …
## $ `depth__-Inf_40`                                 <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ depth__40_47                                     <dbl> 0, 0, 1, 1, 1, 1, 1, …
## $ depth__47_60                                     <dbl> 1, 1, 0, 0, 0, 0, 0, …
## $ depth__60_Inf                                    <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ `height__-Inf_71`                                <dbl> 0, 1, 0, 0, 0, 0, 0, …
## $ height__71_92                                    <dbl> 0, 0, 1, 0, 0, 0, 0, …
## $ height__92_171                                   <dbl> 1, 0, 0, 1, 1, 1, 1, …
## $ height__171_Inf                                  <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ `width__-Inf_60`                                 <dbl> 1, 0, 1, 1, 1, 1, 1, …
## $ width__60_93                                     <dbl> 0, 1, 0, 0, 0, 0, 0, …
## $ width__93_161.5                                  <dbl> 0, 0, 0, 0, 0, 0, 0, …
## $ width__161.5_Inf                                 <dbl> 0, 0, 0, 0, 0, 0, 0, …
# step 3: correlation
data_correlation <- data_binarized %>%
  correlate(sellable_online__Yes)

# step 4: plot
data_correlation %>%
  correlationfunnel::plot_correlation_funnel()
## Warning: The `size` argument of `element_line()` is deprecated as of ggplot2 3.4.0.
## ℹ Please use the `linewidth` argument instead.
## ℹ The deprecated feature was likely used in the correlationfunnel package.
##   Please report the issue at
##   <https://github.com/business-science/correlationfunnel/issues>.
## This warning is displayed once per session.
## Call `lifecycle::last_lifecycle_warnings()` to see where this warning was
## generated.
## Warning: The `size` argument of `element_rect()` is deprecated as of ggplot2 3.4.0.
## ℹ Please use the `linewidth` argument instead.
## ℹ The deprecated feature was likely used in the correlationfunnel package.
##   Please report the issue at
##   <https://github.com/business-science/correlationfunnel/issues>.
## This warning is displayed once per session.
## Call `lifecycle::last_lifecycle_warnings()` to see where this warning was
## generated.
## Warning: ggrepel: 38 unlabeled data points (too many overlaps). Consider
## increasing max.overlaps

data_clean <- data %>%
  mutate(
    category = as.factor(category),
    sellable_online = factor(sellable_online, levels = c(FALSE, TRUE), labels = c("No", "Yes")),
    other_colors = as.factor(other_colors),
    designer = as.factor(designer)
  ) %>%
  select(-`...1`, -item_id, -link, -short_description, -old_price)

#split Data

set.seed(1234)

data_split <- initial_split(data_clean, strata = sellable_online)
data_train <- training(data_split)
data_test <- testing(data_split)

data_cv <- vfold_cv(data_train, strata = sellable_online)

Preprocess data

xgboost_recipe <- recipe(sellable_online ~ ., data = data_train) %>%
  step_impute_median(all_numeric_predictors()) %>%
  step_novel(all_nominal_predictors()) %>%
  step_unknown(all_nominal_predictors()) %>%
  step_dummy(all_nominal_predictors()) %>%
  step_smote(sellable_online)

specify model

xgboost_spec <- 
  boost_tree(
    trees = tune(),
    min_n = tune(),
    tree_depth = tune(),
    learn_rate = tune(),
    loss_reduction = tune(),
    sample_size = tune()
  ) %>%
  set_mode("classification") %>%
  set_engine("xgboost")
xgboost_workflow <- 
  workflow() %>%
  add_recipe(xgboost_recipe) %>%
  add_model(xgboost_spec)

Tune hyperparameters

doParallel::registerDoParallel()

set.seed(65743)
xgboost_tune <- 
  tune_grid(
    xgboost_workflow,
    resamples = data_cv,
    grid = 5,
    metrics = metric_set(accuracy, roc_auc),
    control = control_grid(save_pred = TRUE)
  )
## → A | warning: No event observations were detected in `truth` with event level 'No'.
## There were issues with some computations   A: x5There were issues with some computations   A: x5

Model evaluation

Identify optimal values for hyperparameters

collect_predictions(xgboost_tune) %>%
  roc_curve(sellable_online, .pred_Yes) %>%
  autoplot()

Fit the model for the last time

xgboost_last <- xgboost_workflow %>%
  finalize_workflow(select_best(xgboost_tune, metric = "accuracy")) %>%
  last_fit(data_split)

collect_metrics(xgboost_last)
## # A tibble: 3 × 4
##   .metric     .estimator .estimate .config        
##   <chr>       <chr>          <dbl> <chr>          
## 1 accuracy    binary       0.995   pre0_mod0_post0
## 2 roc_auc     binary       0.953   pre0_mod0_post0
## 3 brier_class binary       0.00375 pre0_mod0_post0
collect_predictions(xgboost_last) %>%
  yardstick::conf_mat(sellable_online, .pred_class) %>%
  autoplot()

Variable importance

library(vip)
## 
## Attaching package: 'vip'
## The following object is masked from 'package:utils':
## 
##     vi
xgboost_fit <- xgboost_workflow %>%
  finalize_workflow(select_best(xgboost_tune, metric = "accuracy")) %>%
  fit(data_train)

xgboost_fit %>%
  extract_fit_parsnip() %>%
  vip()