101 lines
3.7 KiB
R
101 lines
3.7 KiB
R
# Here we are going to try training a model with categorical features
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# Load libraries
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library(data.table)
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library(lightgbm)
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# Load data and look at the structure
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#
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# Classes 'data.table' and 'data.frame': 4521 obs. of 17 variables:
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# $ age : int 30 33 35 30 59 35 36 39 41 43 ...
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# $ job : chr "unemployed" "services" "management" "management" ...
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# $ marital : chr "married" "married" "single" "married" ...
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# $ education: chr "primary" "secondary" "tertiary" "tertiary" ...
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# $ default : chr "no" "no" "no" "no" ...
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# $ balance : int 1787 4789 1350 1476 0 747 307 147 221 -88 ...
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# $ housing : chr "no" "yes" "yes" "yes" ...
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# $ loan : chr "no" "yes" "no" "yes" ...
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# $ contact : chr "cellular" "cellular" "cellular" "unknown" ...
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# $ day : int 19 11 16 3 5 23 14 6 14 17 ...
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# $ month : chr "oct" "may" "apr" "jun" ...
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# $ duration : int 79 220 185 199 226 141 341 151 57 313 ...
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# $ campaign : int 1 1 1 4 1 2 1 2 2 1 ...
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# $ pdays : int -1 339 330 -1 -1 176 330 -1 -1 147 ...
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# $ previous : int 0 4 1 0 0 3 2 0 0 2 ...
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# $ poutcome : chr "unknown" "failure" "failure" "unknown" ...
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# $ y : chr "no" "no" "no" "no" ...
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data(bank, package = "lightgbm")
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str(bank)
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# We are dividing the dataset into two: one train, one validation
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bank_train <- bank[1L:4000L, ]
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bank_test <- bank[4001L:4521L, ]
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# We must now transform the data to fit in LightGBM
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# For this task, we use lgb.convert_with_rules
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# The function transforms the data into a fittable data
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#
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# Classes 'data.table' and 'data.frame': 521 obs. of 17 variables:
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# $ age : int 53 36 58 26 34 55 55 34 41 38 ...
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# $ job : num 1 10 10 9 10 2 2 3 3 4 ...
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# $ marital : num 1 2 1 3 3 2 2 2 1 1 ...
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# $ education: num 2 2 2 2 2 1 2 3 2 2 ...
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# $ default : num 1 1 1 1 1 1 1 1 1 1 ...
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# $ balance : int 26 191 -123 -147 179 1086 471 105 1588 70 ...
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# $ housing : num 2 1 1 1 1 2 2 2 2 1 ...
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# $ loan : num 1 1 1 1 1 1 1 1 2 1 ...
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# $ contact : num 1 1 1 3 1 1 3 3 3 1 ...
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# $ day : int 7 31 5 4 19 6 30 28 20 27 ...
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# $ month : num 9 2 2 7 2 9 9 9 7 11 ...
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# $ duration : int 56 69 131 95 294 146 58 249 10 255 ...
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# $ campaign : int 1 1 2 2 3 1 2 2 8 3 ...
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# $ pdays : int 359 -1 -1 -1 -1 272 -1 -1 -1 148 ...
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# $ previous : int 1 0 0 0 0 2 0 0 0 1 ...
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# $ poutcome : num 1 4 4 4 4 1 4 4 4 3 ...
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# $ y : num 1 1 1 1 1 1 1 1 1 2 ...
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bank_rules <- lgb.convert_with_rules(data = bank_train)
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bank_train <- bank_rules$data
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bank_test <- lgb.convert_with_rules(data = bank_test, rules = bank_rules$rules)$data
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str(bank_test)
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# Remove 1 to label because it must be between 0 and 1
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bank_train$y <- bank_train$y - 1L
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bank_test$y <- bank_test$y - 1L
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# Data input to LightGBM must be a matrix, without the label
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my_data_train <- as.matrix(bank_train[, 1L:16L, with = FALSE])
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my_data_test <- as.matrix(bank_test[, 1L:16L, with = FALSE])
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# Creating the LightGBM dataset with categorical features
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# The categorical features can be passed to lgb.train to not copy and paste a lot
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dtrain <- lgb.Dataset(
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data = my_data_train
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, label = bank_train$y
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, categorical_feature = c(2L, 3L, 4L, 5L, 7L, 8L, 9L, 11L, 16L)
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)
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dtest <- lgb.Dataset.create.valid(
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dtrain
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, data = my_data_test
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, label = bank_test$y
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)
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# We can now train a model
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params <- list(
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objective = "binary"
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, metric = "l2"
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, min_data = 1L
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, learning_rate = 0.1
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, min_hessian = 1.0
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, max_depth = 2L
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)
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model <- lgb.train(
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params = params
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, data = dtrain
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, nrounds = 100L
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, valids = list(train = dtrain, valid = dtest)
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)
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# Try to find split_feature: 11
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# If you find it, it means it used a categorical feature in the first tree
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lgb.dump(model, num_iteration = 1L)
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