Python 데이터 분석

NaiveBayes 분류모델 - GaussanNB 예제

코딩탕탕 2022. 11. 24. 18:14

 

 

<작성자 코드>

import pandas as pd
from sklearn.model_selection import train_test_split
from sklearn.naive_bayes import GaussianNB
from sklearn.metrics import accuracy_score
from sklearn import metrics
from sklearn.preprocessing import LabelEncoder
from xgboost import plot_importance
import matplotlib.pyplot as plt
import xgboost as xgb


df = pd.read_csv('../testdata/mushrooms.csv')
print(df.head(3))
print(df.info())

le = LabelEncoder() # for 문으로 각 칼럼들을 넣어 인코딩하였다.
for col in df.columns:
    df[col] = le.fit_transform(df[col])
print(df.head(3))

x = df.drop(columns = ['class'])
y = df['class']

print(x[:3])
print(y[:3])

# 8 : 2 split
x_train, x_test, y_train, y_test = train_test_split(x, y, test_size = 0.2, random_state = 1)
print(x_train.shape, x_test.shape, y_train.shape, y_test.shape) # (6499, 22) (1625, 22) (6499,) (1625,)

# 주요 변수 모델링 및 시각화
model = xgb.XGBClassifier(booster = 'gbtree', max_depth = 6, n_estimators=500 ).fit(x_train, y_train)
pred = model.predict(x_test)

fig, ax = plt.subplots(figsize=(10, 12))
plot_importance(model, ax = ax)
plt.show()

features = df[['spore-print-color', 'odor', 'gill-size', 'cap-color', 'population']]
labels = df['class']

# 8 : 2 split
x_train, x_test, y_train, y_test = train_test_split(features, labels, test_size = 0.2, random_state = 1)
print(x_train.shape, x_test.shape, y_train.shape, y_test.shape) # (6499, 22) (1625, 22) (6499,) (1625,)

# model
gmodel = GaussianNB()
gmodel.fit(x_train, y_train)

pred = gmodel.predict(x_test)
print('예측값 :', pred[:10])
print('실제값 :', y_test[:10].values)

acc = sum(y_test == pred) / len(pred)
print('acc :', acc)
print('acc :', accuracy_score(y_test, pred))

# kfold
from sklearn import model_selection
cross_val = model_selection.cross_val_score(gmodel, x, y, cv = 5)
print('교차 검증 :', cross_val)
print('교차 검증 평균값 :', cross_val.mean())



<console>
  class cap-shape cap-surface  ... spore-print-color population habitat
0     p         x           s  ...                 k          s       u
1     e         x           s  ...                 n          n       g
2     e         b           s  ...                 n          n       m

[3 rows x 23 columns]
<class 'pandas.core.frame.DataFrame'>
RangeIndex: 8124 entries, 0 to 8123
Data columns (total 23 columns):
 #   Column                    Non-Null Count  Dtype 
---  ------                    --------------  ----- 
 0   class                     8124 non-null   object
 1   cap-shape                 8124 non-null   object
 2   cap-surface               8124 non-null   object
 3   cap-color                 8124 non-null   object
 4   bruises                   8124 non-null   object
 5   odor                      8124 non-null   object
 6   gill-attachment           8124 non-null   object
 7   gill-spacing              8124 non-null   object
 8   gill-size                 8124 non-null   object
 9   gill-color                8124 non-null   object
 10  stalk-shape               8124 non-null   object
 11  stalk-root                8124 non-null   object
 12  stalk-surface-above-ring  8124 non-null   object
 13  stalk-surface-below-ring  8124 non-null   object
 14  stalk-color-above-ring    8124 non-null   object
 15  stalk-color-below-ring    8124 non-null   object
 16  veil-type                 8124 non-null   object
 17  veil-color                8124 non-null   object
 18  ring-number               8124 non-null   object
 19  ring-type                 8124 non-null   object
 20  spore-print-color         8124 non-null   object
 21  population                8124 non-null   object
 22  habitat                   8124 non-null   object
dtypes: object(23)
memory usage: 1.4+ MB
None
   class  cap-shape  cap-surface  ...  spore-print-color  population  habitat
0      1          5            2  ...                  2           3        5
1      0          5            2  ...                  3           2        1
2      0          0            2  ...                  3           2        3

[3 rows x 23 columns]
   cap-shape  cap-surface  cap-color  ...  spore-print-color  population  habitat
0          5            2          4  ...                  2           3        5
1          5            2          9  ...                  3           2        1
2          0            2          8  ...                  3           2        3

[3 rows x 22 columns]
0    1
1    0
2    0
Name: class, dtype: int32
(6499, 22) (1625, 22) (6499,) (1625,)
(6499, 5) (1625, 5) (6499,) (1625,)
예측값 : [0 1 1 1 1 1 1 0 0 0]
실제값 : [0 1 1 1 0 1 1 0 1 1]
acc : 0.7341538461538462
acc : 0.7341538461538462
교차 검증 : [0.72923077 0.96123077 0.79261538 0.65230769 0.49445813]
교차 검증 평균값 : 0.7259685486926866

 

주요 변수들 시각화