Goal: Build a regression model to predict the cost (cost_km_millions) of the transit project. Click here for the data.

Import Data

transit_cost <- readr::read_csv('https://raw.githubusercontent.com/rfordatascience/tidytuesday/main/data/2021/2021-01-05/transit_cost.csv')
## Rows: 544 Columns: 20
## ── Column specification ────────────────────────────────────────────────────────
## Delimiter: ","
## chr (11): country, city, line, start_year, end_year, tunnel_per, source1, cu...
## dbl  (9): e, rr, length, tunnel, stations, cost, year, ppp_rate, cost_km_mil...
## 
## 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.
skimr::skim(transit_cost)
Data summary
Name transit_cost
Number of rows 544
Number of columns 20
_______________________
Column type frequency:
character 11
numeric 9
________________________
Group variables None

Variable type: character

skim_variable n_missing complete_rate min max empty n_unique whitespace
country 7 0.99 2 2 0 56 0
city 7 0.99 4 16 0 140 0
line 7 0.99 2 46 0 366 0
start_year 53 0.90 4 9 0 40 0
end_year 71 0.87 1 4 0 36 0
tunnel_per 32 0.94 5 7 0 134 0
source1 12 0.98 4 54 0 17 0
currency 7 0.99 2 3 0 39 0
real_cost 0 1.00 1 10 0 534 0
source2 10 0.98 3 16 0 12 0
reference 19 0.97 3 302 0 350 0

Variable type: numeric

skim_variable n_missing complete_rate mean sd p0 p25 p50 p75 p100 hist
e 7 0.99 7738.76 463.23 7136.00 7403.00 7705.00 7977.00 9510.00 ▇▇▂▁▁
rr 8 0.99 0.06 0.24 0.00 0.00 0.00 0.00 1.00 ▇▁▁▁▁
length 5 0.99 58.34 621.20 0.60 6.50 15.77 29.08 12256.98 ▇▁▁▁▁
tunnel 32 0.94 29.38 344.04 0.00 3.40 8.91 21.52 7790.78 ▇▁▁▁▁
stations 15 0.97 13.81 13.70 0.00 4.00 10.00 20.00 128.00 ▇▁▁▁▁
cost 7 0.99 805438.12 6708033.07 0.00 2289.00 11000.00 27000.00 90000000.00 ▇▁▁▁▁
year 7 0.99 2014.91 5.64 1987.00 2012.00 2016.00 2019.00 2027.00 ▁▁▂▇▂
ppp_rate 9 0.98 0.66 0.87 0.00 0.24 0.26 1.00 5.00 ▇▂▁▁▁
cost_km_millions 2 1.00 232.98 257.22 7.79 134.86 181.25 241.43 3928.57 ▇▁▁▁▁
data <- transit_cost %>%
    
    # Treat missing values
    select(-cost, -currency, -source2, -source1, -reference, -line, -real_cost) %>%
    mutate(across(c(start_year, end_year), as.numeric)) %>%
    
     # Convert character columns to factors
    mutate(across(where(is.character), as.factor)) %>%
    
    # Convert rr to a factor
    mutate(rr = factor(rr)) %>%
    
    # Remove missing values
    na.omit() %>%
    
    # log transform variables with pos-skewed distributions
    mutate(cost_km_millions = log(cost_km_millions))
## Warning: There were 2 warnings in `mutate()`.
## The first warning was:
## ℹ In argument: `across(c(start_year, end_year), as.numeric)`.
## Caused by warning:
## ! NAs introduced by coercion
## ℹ Run `dplyr::last_dplyr_warnings()` to see the 1 remaining warning.
skimr::skim(data)
Data summary
Name data
Number of rows 436
Number of columns 13
_______________________
Column type frequency:
factor 4
numeric 9
________________________
Group variables None

Variable type: factor

skim_variable n_missing complete_rate ordered n_unique top_counts
country 0 1 FALSE 55 CN: 169, IN: 27, TR: 20, ES: 15
city 0 1 FALSE 135 Bei: 21, Sha: 18, Ist: 15, Mum: 13
rr 0 1 FALSE 2 0: 404, 1: 32
tunnel_per 0 1 FALSE 118 100: 245, 0.0: 51, 20.: 3, 35.: 3

Variable type: numeric

skim_variable n_missing complete_rate mean sd p0 p25 p50 p75 p100 hist
e 0 1 7694.72 482.20 7136.00 7354.75 7589.50 7923.50 9510.00 ▇▅▂▁▁
start_year 0 1 2012.99 6.89 1982.00 2009.00 2015.00 2018.00 2025.00 ▁▁▂▇▇
end_year 0 1 2018.88 6.49 1987.00 2016.00 2020.00 2023.00 2030.00 ▁▁▂▇▆
length 0 1 20.59 21.93 0.60 6.10 14.75 28.20 200.00 ▇▁▁▁▁
tunnel 0 1 13.64 15.50 0.00 3.27 8.40 20.00 160.00 ▇▁▁▁▁
stations 0 1 13.77 14.03 0.00 4.00 10.00 20.00 128.00 ▇▁▁▁▁
year 0 1 2014.51 5.91 1987.00 2012.00 2016.00 2018.00 2027.00 ▁▁▂▇▂
ppp_rate 0 1 0.71 0.88 0.00 0.24 0.27 1.25 5.00 ▇▂▁▁▁
cost_km_millions 0 1 5.23 0.63 2.05 4.89 5.22 5.49 8.28 ▁▁▇▁▁

Explore Data

Identify good predictors.

Length

data %>%
    ggplot(aes(cost_km_millions, length)) +
    scale_y_log10() +
    geom_point()

Tunnel

data %>%
    ggplot(aes(cost_km_millions, tunnel)) +
    scale_y_log10() +
    geom_point()
## Warning in scale_y_log10(): log-10 transformation introduced infinite values.

Stations

data %>%
    ggplot(aes(cost_km_millions, as.factor(year))) +
    geom_boxplot()

city

data %>%
    
    group_by(city) %>%
    filter(n() > 5) %>%
    ungroup() %>%
    
    # Plot
    ggplot(aes(cost_km_millions, fct_reorder(city, cost_km_millions))) +
    geom_point() +
    labs(y = "City of Transit Project")

EDA shortcut

# Step 1: Prepare data
data_binarized_tbl <- data %>%
    select(-e) %>%
    binarize()

data_binarized_tbl %>% glimpse()
## Rows: 436
## Columns: 84
## $ country__BG                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ country__CA                                         <dbl> 1, 1, 1, 1, 1, 0, …
## $ country__CN                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ country__DE                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ country__ES                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ country__FR                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ country__IN                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ country__IT                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ country__JP                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ country__KR                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ country__RU                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ country__SA                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ country__SE                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ country__TH                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ country__TR                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ country__TW                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ country__US                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ country__VN                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ `country__-OTHER`                                   <dbl> 0, 0, 0, 0, 0, 1, …
## $ city__Bangkok                                       <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Barcelona                                     <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Beijing                                       <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Changchun                                     <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Changsha                                      <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Chengdu                                       <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Chongqing                                     <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Dongguan                                      <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Guangzhou                                     <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Guiyang                                       <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Hangzhou                                      <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Istanbul                                      <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Madrid                                        <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Mumbai                                        <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Nanjing                                       <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__New_York                                      <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Paris                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Riyadh                                        <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Seoul                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Shanghai                                      <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Shenzhen                                      <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Sofia                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Taipei                                        <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Tianjin                                       <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Tokyo                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ city__Toronto                                       <dbl> 0, 1, 1, 1, 1, 0, …
## $ city__Wuhan                                         <dbl> 0, 0, 0, 0, 0, 0, …
## $ `city__-OTHER`                                      <dbl> 1, 0, 0, 0, 0, 1, …
## $ `start_year__-Inf_2009`                             <dbl> 0, 1, 0, 0, 0, 1, …
## $ start_year__2009_2015                               <dbl> 0, 0, 0, 0, 0, 0, …
## $ start_year__2015_2018                               <dbl> 0, 0, 0, 0, 0, 0, …
## $ start_year__2018_Inf                                <dbl> 1, 0, 1, 1, 1, 0, …
## $ `end_year__-Inf_2016`                               <dbl> 0, 0, 0, 0, 0, 0, …
## $ end_year__2016_2020                                 <dbl> 0, 1, 0, 0, 0, 1, …
## $ end_year__2020_2023                                 <dbl> 0, 0, 0, 0, 0, 0, …
## $ end_year__2023_Inf                                  <dbl> 1, 0, 1, 1, 1, 0, …
## $ rr__0                                               <dbl> 1, 1, 1, 1, 1, 1, …
## $ rr__1                                               <dbl> 0, 0, 0, 0, 0, 0, …
## $ `length__-Inf_6.1`                                  <dbl> 1, 0, 0, 0, 0, 0, …
## $ length__6.1_14.75                                   <dbl> 0, 1, 1, 0, 1, 1, …
## $ length__14.75_28.2                                  <dbl> 0, 0, 0, 1, 0, 0, …
## $ length__28.2_Inf                                    <dbl> 0, 0, 0, 0, 0, 0, …
## $ `tunnel_per__0.00%`                                 <dbl> 0, 0, 0, 0, 0, 0, …
## $ `tunnel_per__100.00%`                               <dbl> 0, 1, 1, 0, 1, 0, …
## $ `tunnel_per__-OTHER`                                <dbl> 1, 0, 0, 1, 0, 1, …
## $ `tunnel__-Inf_3.275`                                <dbl> 0, 0, 0, 0, 0, 0, …
## $ tunnel__3.275_8.4                                   <dbl> 1, 0, 1, 0, 1, 1, …
## $ tunnel__8.4_20                                      <dbl> 0, 1, 0, 1, 0, 0, …
## $ tunnel__20_Inf                                      <dbl> 0, 0, 0, 0, 0, 0, …
## $ `stations__-Inf_4`                                  <dbl> 0, 0, 1, 0, 0, 0, …
## $ stations__4_10                                      <dbl> 1, 1, 0, 0, 1, 1, …
## $ stations__10_20                                     <dbl> 0, 0, 0, 1, 0, 0, …
## $ stations__20_Inf                                    <dbl> 0, 0, 0, 0, 0, 0, …
## $ `year__-Inf_2012`                                   <dbl> 0, 0, 0, 0, 0, 1, …
## $ year__2012_2016                                     <dbl> 0, 1, 0, 0, 0, 0, …
## $ year__2016_2018                                     <dbl> 1, 0, 1, 0, 0, 0, …
## $ year__2018_Inf                                      <dbl> 0, 0, 0, 1, 1, 0, …
## $ `ppp_rate__-Inf_0.2379`                             <dbl> 0, 0, 0, 0, 0, 0, …
## $ ppp_rate__0.2379_0.266                              <dbl> 0, 0, 0, 0, 0, 0, …
## $ ppp_rate__0.266_1.25                                <dbl> 1, 1, 1, 1, 1, 0, …
## $ ppp_rate__1.25_Inf                                  <dbl> 0, 0, 0, 0, 0, 1, …
## $ `cost_km_millions__-Inf_4.89022561868544`           <dbl> 0, 0, 0, 0, 0, 0, …
## $ cost_km_millions__4.89022561868544_5.21539741232945 <dbl> 0, 0, 0, 0, 0, 0, …
## $ cost_km_millions__5.21539741232945_5.49422035213027 <dbl> 0, 0, 0, 0, 0, 0, …
## $ cost_km_millions__5.49422035213027_Inf              <dbl> 1, 1, 1, 1, 1, 1, …
# Step 2: Correlate
data_corr_tbl <- data_binarized_tbl %>%
    correlate(cost_km_millions__5.49422035213027_Inf)

data_corr_tbl
## # A tibble: 84 × 3
##    feature          bin                               correlation
##    <fct>            <chr>                                   <dbl>
##  1 cost_km_millions 5.49422035213027_Inf                    1    
##  2 cost_km_millions -Inf_4.89022561868544                  -0.333
##  3 cost_km_millions 4.89022561868544_5.21539741232945      -0.333
##  4 cost_km_millions 5.21539741232945_5.49422035213027      -0.333
##  5 country          US                                      0.304
##  6 country          CN                                     -0.264
##  7 country          -OTHER                                  0.196
##  8 city             New_York                                0.187
##  9 tunnel_per       0.00%                                  -0.161
## 10 city             -OTHER                                  0.160
## # ℹ 74 more rows
# Step 3: Plot 
data_corr_tbl %>%
    plot_correlation_funnel()
## Warning: ggrepel: 44 unlabeled data points (too many overlaps). Consider
## increasing max.overlaps

Build Models

Split data

#data <- sample_n(data, 200)

# Split into training and testing dataset
set.seed(1234)
data_split <- rsample::initial_split(data)
data_train <- training(data_split)
data_test  <- testing(data_split)

# Further split training dataset for cross-validation
set.seed(2345)
data_cv <- rsample::vfold_cv(data_train)
data_cv
## #  10-fold cross-validation 
## # A tibble: 10 × 2
##    splits           id    
##    <list>           <chr> 
##  1 <split [294/33]> Fold01
##  2 <split [294/33]> Fold02
##  3 <split [294/33]> Fold03
##  4 <split [294/33]> Fold04
##  5 <split [294/33]> Fold05
##  6 <split [294/33]> Fold06
##  7 <split [294/33]> Fold07
##  8 <split [295/32]> Fold08
##  9 <split [295/32]> Fold09
## 10 <split [295/32]> Fold10

Evaluate Models

usemodels::use_xgboost(cost_km_millions ~ ., data = data_train)
## xgboost_recipe <- 
##   recipe(formula = cost_km_millions ~ ., data = data_train) %>% 
##   step_zv(all_predictors()) 
## 
## 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) 
## 
## set.seed(24468)
## xgboost_tune <-
##   tune_grid(xgboost_workflow, resamples = stop("add your rsample object"), grid = stop("add number of candidate points"))
# Specify recipe
xgboost_recipe <- 
    recipe(formula = cost_km_millions ~ ., data = data_train) %>% 
    recipes::update_role(e, new_role = "id variable") %>%
    step_other(country, city) %>%
    step_dummy(country, city, rr, tunnel_per, one_hot = TRUE) %>%
    step_YeoJohnson(ppp_rate, stations, tunnel, length)
    
    
xgboost_recipe %>% prep() %>% juice() %>% glimpse()
## Rows: 327
## Columns: 150
## $ e                   <dbl> 7808, 7945, 8177, 7338, 7360, 8139, 7408, 9462, 81…
## $ start_year          <dbl> 2019, 2016, 2014, 2013, 2010, 2005, 2007, 2016, 20…
## $ end_year            <dbl> 2024, 2020, 2017, 2019, 2013, 2008, 2014, 2020, 20…
## $ length              <dbl> 2.3609445, 4.0888821, 4.2880937, 4.1664966, 1.7520…
## $ tunnel              <dbl> 2.6074533, 4.8338475, 2.2244221, 4.9402665, 0.0000…
## $ stations            <dbl> 2.0794415, 2.8903718, 3.0445224, 3.3672958, 1.3862…
## $ year                <dbl> 2019, 2015, 2013, 2016, 2012, 2005, 2011, 2013, 20…
## $ ppp_rate            <dbl> 0.181586895, 0.192966273, 0.512621127, 0.503748075…
## $ cost_km_millions    <dbl> 5.423672, 5.178520, 5.410202, 4.926078, 4.595601, …
## $ country_CN          <dbl> 1, 1, 0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 0, 1, 0, 1,…
## $ country_IN          <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0,…
## $ country_other       <dbl> 0, 0, 1, 1, 1, 0, 1, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0,…
## $ city_Beijing        <dbl> 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ city_other          <dbl> 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,…
## $ rr_X0               <dbl> 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,…
## $ rr_X1               <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X0.00.   <dbl> 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0,…
## $ tunnel_per_X100.00. <dbl> 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0,…
## $ tunnel_per_X12.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X12.41.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X13.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X13.43.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X14.00.  <dbl> 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X14.32.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X14.45.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X15.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X15.96.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X16.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X16.03.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X18.69.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X19.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X20.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X21.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X21.05.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X21.33.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X23.22.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X25.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X26.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X26.67.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X28.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X29.08.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X29.31.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X31.99.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X32.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X33.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X33.90.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X34.55.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X34.58.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X34.86.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X35.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X35.11.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X36.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X38.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X38.95.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X39.01.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X39.47.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X4.00.   <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0,…
## $ tunnel_per_X40.48.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X42.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X42.63.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X43.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X43.18.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X44.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X44.83.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X45.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X46.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X47.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X47.11.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X48.49.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X49.29.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X50.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X51.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X51.12.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X52.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X52.98.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X53.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X54.38.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,…
## $ tunnel_per_X55.61.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X57.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X59.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X59.46.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X6.00.   <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X60.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X60.26.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X62.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X62.57.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X63.40.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X63.61.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X63.83.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X64.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X65.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X65.24.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X65.98.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X66.91.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X68.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X69.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X69.19.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X69.81.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X69.83.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X7.00.   <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X70.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X70.07.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X70.25.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X71.81.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X73.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X73.45.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X74.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0,…
## $ tunnel_per_X74.34.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X75.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X77.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X78.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X79.01.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X79.36.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X8.00.   <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X80.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X80.28.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X81.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X81.15.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X81.25.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X82.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X83.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X84.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X84.11.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X84.29.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X84.55.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X85.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X86.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X86.54.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X87.21.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X87.72.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X89.92.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X90.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X90.13.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X91.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X91.16.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X92.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X92.33.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X93.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X93.02.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X93.38.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X95.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X95.17.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X95.93.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X96.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X96.21.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X96.68.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X97.00.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X97.54.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X98.44.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
## $ tunnel_per_X98.50.  <dbl> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,…
# Specify model
xgboost_spec <- 
  boost_tree(trees = tune(), min_n = tune(), mtry = tune(), learn_rate = tune()) %>% 
  set_mode("regression") %>% 
  set_engine("xgboost") 

# Combine recipe and model using workflow
xgboost_workflow <- 
  workflow() %>% 
  add_recipe(xgboost_recipe) %>% 
  add_model(xgboost_spec) 


# Tune hyperparmeters
set.seed(234)
xgboost_tune <-
  tune_grid(xgboost_workflow, 
            resamples = data_cv,
            grid = 5)
## i Creating pre-processing data to finalize unknown parameter: mtry

Evaluate Models

tune::show_best(xgboost_tune, metric = "rmse")
## # A tibble: 5 × 10
##    mtry trees min_n learn_rate .metric .estimator  mean     n std_err .config   
##   <int> <int> <int>      <dbl> <chr>   <chr>      <dbl> <int>   <dbl> <chr>     
## 1    55  1059     6    0.00957 rmse    standard   0.508    10  0.0346 Preproces…
## 2   145  1554    39    0.0228  rmse    standard   0.522    10  0.0290 Preproces…
## 3    14  1981    28    0.0379  rmse    standard   0.524    10  0.0314 Preproces…
## 4    85   258    23    0.134   rmse    standard   0.526    10  0.0380 Preproces…
## 5   104   436    10    0.00166 rmse    standard   2.38     10  0.0416 Preproces…
# Update the model by selecting the best hyperparameters.
xgboost_fw <- tune::finalize_workflow(xgboost_workflow,
                        tune::select_best(xgboost_tune, metric = "rmse"))

# Fit the model on the entire training data and test it on the test data.
data_fit <- tune::last_fit(xgboost_fw, data_split)
tune::collect_metrics(data_fit) 
## # A tibble: 2 × 4
##   .metric .estimator .estimate .config             
##   <chr>   <chr>          <dbl> <chr>               
## 1 rmse    standard       0.511 Preprocessor1_Model1
## 2 rsq     standard       0.394 Preprocessor1_Model1
tune::collect_predictions(data_fit) %>%
    ggplot(aes(cost_km_millions, .pred)) +
    geom_point(fill = "midnightblue") +
    geom_abline(lty = 2, color = "gray50") +
    coord_fixed()

Make Predictions