1. 樸素貝葉斯分類器（Python實現+詳細源碼原理）
1、貝葉斯公式的本質： <u>由因到果，由果推因</u>
2、貝葉斯公式：
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1、樸素貝葉斯公式
x1，x2,...xn為特徵集合，y為分類結果
樸素貝葉斯假設各個特徵之間相互獨立
分母相同情況下，我們只要保證分子最大
訓練數據集
long,not_long,sweet,not_sweet,yellow,not_yellow,species
400,100,350,150,450,50,banana
0,300,150,150,300,0,orange
100,100,150,50,50,150,other_fruit
測試數據集
long,sweet,yellow
not_long,not_sweet,not_yellow
not_long,sweet,not_yellow
not_long,sweet,yellow
not_long,sweet,yellow
not_long,not_sweet,not_yellow
long,not_sweet,not_yellow
long,not_sweet,not_yellow
long,not_sweet,not_yellow
long,not_sweet,not_yellow
long,not_sweet,yellow
not_long,not_sweet,yellow
not_long,not_sweet,yellow
long,not_sweet,not_yellow
not_long,not_sweet,yellow
結果
特徵值：[not_long, not_sweet, not_yellow]
預測結果：{'banana': 0.003, 'orange': 0.0, 'other_fruit': 0.018750000000000003}
水果類別：other_fruit
特徵值：[not_long, sweet, not_yellow]
預測結果：{'banana': 0.006999999999999999, 'orange': 0.0, 'other_fruit': 0.05625000000000001}
水果類別：other_fruit
特徵值：[not_long, sweet, yellow]
預測結果：{'banana': 0.063, 'orange': 0.15, 'other_fruit': 0.018750000000000003}
水果類別：orange
特徵值：[not_long, sweet, yellow]
預測結果：{'banana': 0.063, 'orange': 0.15, 'other_fruit': 0.018750000000000003}
水果類別：orange
特徵值：[not_long, not_sweet, not_yellow]
預測結果：{'banana': 0.003, 'orange': 0.0, 'other_fruit': 0.018750000000000003}
水果類別：other_fruit
特徵值：[long, not_sweet, not_yellow]
預測結果：{'banana': 0.012, 'orange': 0.0, 'other_fruit': 0.018750000000000003}
水果類別：other_fruit
特徵值：[long, not_sweet, not_yellow]
預測結果：{'banana': 0.012, 'orange': 0.0, 'other_fruit': 0.018750000000000003}
水果類別：other_fruit
特徵值：[long, not_sweet, not_yellow]
預測結果：{'banana': 0.012, 'orange': 0.0, 'other_fruit': 0.018750000000000003}
水果類別：other_fruit
特徵值：[long, not_sweet, not_yellow]
預測結果：{'banana': 0.012, 'orange': 0.0, 'other_fruit': 0.018750000000000003}
水果類別：other_fruit
特徵值：[long, not_sweet, yellow]
預測結果：{'banana': 0.108, 'orange': 0.0, 'other_fruit': 0.00625}
水果類別：banana
特徵值：[not_long, not_sweet, yellow]
預測結果：{'banana': 0.027, 'orange': 0.15, 'other_fruit': 0.00625}
水果類別：orange
特徵值：[not_long, not_sweet, yellow]
預測結果：{'banana': 0.027, 'orange': 0.15, 'other_fruit': 0.00625}
水果類別：orange
特徵值：[long, not_sweet, not_yellow]
預測結果：{'banana': 0.012, 'orange': 0.0, 'other_fruit': 0.018750000000000003}
水果類別：other_fruit
特徵值：[not_long, not_sweet, yellow]
預測結果：{'banana': 0.027, 'orange': 0.15, 'other_fruit': 0.00625}
水果類別：orange