8、特征选择

 1 from sklearn.feature_selection import VarianceThreshold  # 特征选择API
 2 
 3 # 特征选择--删除低方差的特征
 4 def var(da, i):
 5     var = VarianceThreshold(threshold=i)
 6     data = var.fit_transform(da)
 7     return data
 8 
 9 if __name__ == "__main__":
10     data = [[0, 2, 0, 3], [0,  1, 4, 3], [0, 1, 1, 3]]
11     print("threshold=0.0时的返回值:\n", var(data, 0.0))
12     print("threshold=1.0时的返回值:\n", var(data, 1.0))
13     print("threshold=2.0时的返回值:\n", var(data, 2.0))