Titanic with ML(LabelEncoder, one-hot encoding, Nomalization and Standard Scaling)
[Notice] [ML_3]
Titanic with ML(LabelEncoder, one-hot encoding, Nomalization and Standard Scaling)
import numpy as np
import pandas as pd
train = pd.read_csv('https://bit.ly/fc-ml-titanic')
Label Encoding: Converts text (categorical) to numeric (numerical)
train.info()
<class 'pandas.core.frame.DataFrame'> RangeIndex: 891 entries, 0 to 890 Data columns (total 12 columns): # Column Non-Null Count Dtype --- ------ -------------- ----- 0 PassengerId 891 non-null int64 1 Survived 891 non-null int64 2 Pclass 891 non-null int64 3 Name 891 non-null object 4 Sex 891 non-null object 5 Age 714 non-null float64 6 SibSp 891 non-null int64 7 Parch 891 non-null int64 8 Ticket 891 non-null object 9 Fare 891 non-null float64 10 Cabin 204 non-null object 11 Embarked 889 non-null object dtypes: float64(2), int64(5), object(5) memory usage: 83.7+ KB
def convert(data):
if data == 'male':
return 1
elif data == 'female':
return 0
train['Sex'].value_counts()
male 577 female 314 Name: Sex, dtype: int64
train['Sex'].apply(convert)
0 1 1 0 2 0 3 0 4 1 .. 886 1 887 0 888 0 889 1 890 1 Name: Sex, Length: 891, dtype: int64
LabelEncoder
from sklearn.preprocessing import LabelEncoder
le = LabelEncoder()
le.fit_transform(train['Sex'])
array([1, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 0, 0, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1])
train['Sex_num'] = le.fit_transform(train['Sex'])
train['Sex_num'].value_counts()
1 577 0 314 Name: Sex_num, dtype: int64
le.classes_
array(['female', 'male'], dtype=object)
le.inverse_transform([0, 1, 1, 0, 0, 1, 1])
array(['female', 'male', 'male', 'female', 'female', 'male', 'male'], dtype=object)
If NaN values are included, LabelEncoder
does not work properly.
train['Embarked'] = train['Embarked'].fillna('S')
le.fit_transform(train['Embarked'])
array([2, 0, 2, 2, 2, 1, 2, 2, 2, 0, 2, 2, 2, 2, 2, 2, 1, 2, 2, 0, 2, 2, 1, 2, 2, 2, 0, 2, 1, 2, 0, 0, 1, 2, 0, 2, 0, 2, 2, 0, 2, 2, 0, 0, 1, 2, 1, 1, 0, 2, 2, 2, 0, 2, 0, 2, 2, 0, 2, 2, 0, 2, 2, 2, 0, 0, 2, 2, 2, 2, 2, 2, 2, 0, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 0, 2, 2, 0, 2, 1, 2, 0, 2, 2, 2, 0, 2, 2, 0, 1, 2, 0, 2, 0, 2, 2, 2, 2, 0, 2, 2, 2, 0, 0, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 0, 2, 2, 0, 2, 2, 2, 0, 2, 2, 2, 2, 1, 2, 1, 2, 2, 2, 2, 2, 0, 0, 1, 2, 1, 2, 2, 2, 2, 0, 2, 2, 2, 0, 1, 0, 2, 2, 2, 2, 1, 0, 2, 2, 0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 1, 2, 2, 0, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 0, 2, 0, 2, 1, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 0, 1, 2, 2, 2, 1, 2, 1, 2, 2, 2, 2, 0, 2, 2, 2, 1, 2, 0, 0, 2, 2, 0, 0, 2, 2, 0, 1, 1, 2, 1, 2, 2, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 2, 2, 2, 0, 2, 2, 1, 2, 2, 0, 2, 2, 2, 0, 1, 2, 2, 2, 2, 2, 2, 0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 2, 0, 2, 2, 2, 1, 1, 2, 0, 0, 2, 1, 2, 0, 0, 1, 0, 0, 2, 2, 0, 2, 0, 2, 0, 0, 2, 0, 0, 2, 2, 2, 2, 2, 2, 1, 0, 2, 2, 2, 0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 2, 2, 2, 2, 2, 2, 2, 0, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 2, 2, 2, 0, 0, 2, 0, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 1, 0, 2, 2, 2, 0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 2, 2, 0, 2, 2, 2, 2, 2, 0, 2, 0, 0, 2, 2, 2, 2, 1, 1, 2, 2, 0, 2, 2, 2, 2, 1, 2, 2, 0, 2, 2, 2, 1, 2, 2, 2, 2, 0, 0, 0, 1, 2, 2, 2, 2, 2, 0, 0, 0, 2, 2, 2, 0, 2, 0, 2, 2, 2, 2, 0, 2, 2, 0, 2, 2, 0, 2, 1, 0, 2, 2, 0, 0, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 0, 2, 2, 2, 2, 1, 2, 2, 2, 2, 0, 2, 2, 0, 2, 0, 0, 2, 2, 0, 2, 2, 2, 0, 2, 1, 2, 2, 2, 2, 0, 0, 2, 2, 2, 2, 0, 2, 2, 2, 0, 2, 2, 2, 1, 1, 2, 2, 2, 2, 2, 2, 0, 2, 0, 2, 2, 2, 1, 2, 2, 1, 2, 2, 0, 2, 2, 2, 2, 2, 2, 2, 2, 0, 2, 2, 0, 0, 2, 0, 2, 2, 2, 2, 2, 1, 1, 2, 2, 1, 2, 0, 2, 0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 1, 0, 2, 2, 2, 0, 2, 2, 2, 2, 2, 0, 2, 0, 2, 2, 2, 1, 0, 2, 0, 2, 0, 1, 2, 2, 2, 2, 2, 0, 0, 2, 2, 2, 2, 2, 0, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 0, 2, 2, 2, 2, 2, 0, 2, 2, 2, 2, 0, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 2, 2, 2, 0, 1, 1, 2, 2, 2, 2, 0, 2, 2, 1, 2, 1, 2, 0, 2, 2, 2, 2, 2, 2, 1, 2, 0, 1, 2, 2, 0, 2, 2, 2, 2, 0, 2, 2, 2, 2, 0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 2, 2, 2, 2, 2, 2, 2, 1, 2, 0, 1, 2, 0, 2, 0, 2, 2, 0, 2, 2, 2, 0, 2, 2, 0, 0, 2, 2, 2, 0, 2, 0, 2, 2, 0, 2, 2, 2, 2, 2, 0, 0, 2, 2, 2, 2, 2, 2, 0, 2, 2, 2, 2, 2, 2, 2, 0, 0, 2, 2, 2, 0, 2, 2, 2, 2, 2, 1, 2, 2, 2, 0, 1])
One Hot Encoding
train = pd.read_csv('https://bit.ly/fc-ml-titanic')
train.head()
PassengerId | Survived | Pclass | Name | Sex | Age | SibSp | Parch | Ticket | Fare | Cabin | Embarked | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
0 | 1 | 0 | 3 | Braund, Mr. Owen Harris | male | 22.0 | 1 | 0 | A/5 21171 | 7.2500 | NaN | S |
1 | 2 | 1 | 1 | Cumings, Mrs. John Bradley (Florence Briggs Th... | female | 38.0 | 1 | 0 | PC 17599 | 71.2833 | C85 | C |
2 | 3 | 1 | 3 | Heikkinen, Miss. Laina | female | 26.0 | 0 | 0 | STON/O2. 3101282 | 7.9250 | NaN | S |
3 | 4 | 1 | 1 | Futrelle, Mrs. Jacques Heath (Lily May Peel) | female | 35.0 | 1 | 0 | 113803 | 53.1000 | C123 | S |
4 | 5 | 0 | 3 | Allen, Mr. William Henry | male | 35.0 | 0 | 0 | 373450 | 8.0500 | NaN | S |
train['Embarked'].value_counts()
S 644 C 168 Q 77 Name: Embarked, dtype: int64
train['Embarked'] = train['Embarked'].fillna('S')
train['Embarked'].value_counts()
S 646 C 168 Q 77 Name: Embarked, dtype: int64
train['Embarked_num'] = LabelEncoder().fit_transform(train['Embarked'])
train['Embarked_num'].value_counts()
2 646 0 168 1 77 Name: Embarked_num, dtype: int64
train['Embarked'][:6]
0 S 1 C 2 S 3 S 4 S 5 Q Name: Embarked, dtype: object
train['Embarked_num'][:6]
0 2 1 0 2 2 3 2 4 2 5 1 Name: Embarked_num, dtype: int32
pd.get_dummies(train['Embarked_num'][:6])
0 | 1 | 2 | |
---|---|---|---|
0 | 0 | 0 | 1 |
1 | 1 | 0 | 0 |
2 | 0 | 0 | 1 |
3 | 0 | 0 | 1 |
4 | 0 | 0 | 1 |
5 | 0 | 1 | 0 |
one_hot = pd.get_dummies(train['Embarked_num'][:6])
one_hot.columns = ['C','Q','S']
one_hot
C | Q | S | |
---|---|---|---|
0 | 0 | 0 | 1 |
1 | 1 | 0 | 0 |
2 | 0 | 0 | 1 |
3 | 0 | 0 | 1 |
4 | 0 | 0 | 1 |
5 | 0 | 1 | 0 |
By separating the column as above, it breaks the relationship between the ‘numeric value’ that occurs while converting category type -> numeric type and changes it to an independent type
One-hot encoding is applied to columns with characteristics of categories (season, port, gender, type, Korean/Japanese/Chinese food…)
Preprocessing: Normalize
If you have different min, max values between columns, matching the minimum/maximum values through normalization
-
Naver Movie Rating (0 to 10): [2, 4, 6, 8, 10]
-
Netflix movie rating (0 to 5): [1, 2, 3, 4, 5
movie = {'naver': [2, 4, 6, 8, 10],
'netflix': [1, 2, 3, 4, 5]
}
movie = pd.DataFrame(data=movie)
movie
naver | netflix | |
---|---|---|
0 | 2 | 1 |
1 | 4 | 2 |
2 | 6 | 3 |
3 | 8 | 4 |
4 | 10 | 5 |
MinMaxScaler
from sklearn.preprocessing import MinMaxScaler
min_max_scaler = MinMaxScaler()
min_max_movie = min_max_scaler.fit_transform(movie)
pd.DataFrame(min_max_movie, columns=['naver', 'netflix'])
naver | netflix | |
---|---|---|
0 | 0.00 | 0.00 |
1 | 0.25 | 0.25 |
2 | 0.50 | 0.50 |
3 | 0.75 | 0.75 |
4 | 1.00 | 1.00 |
Standard Scaling
converted to have a mean of 0 and a standard deviation of 1
from sklearn.preprocessing import StandardScaler
standard_scaler = StandardScaler()
x = np.arange(10)
# add outlier
x[9] = 1000
x.mean(), x.std()
(103.6, 298.8100399919654)
scaled = standard_scaler.fit_transform(x.reshape(-1, 1))
x.mean(), x.std()
(103.6, 298.8100399919654)
scaled.mean(), scaled.std()
(4.4408920985006264e-17, 1.0)
round(scaled.mean(), 2), scaled.std()
(0.0, 1.0)
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