Scikit學習SVM功能名稱

Question

我正在開發一個使用Scikit學習的SVM分類器。我有378個功能，我發現在適配我的分類器後，我的數據的最佳功能數量是41個。現在我想知道這41個功能究竟是什麼。排名每個功能的重要性，我用：

selector.ranking_ 

這給了我下面的輸出：

array([294, 285, 265, 239, 345, 240, 231, 282, 284, 341, 344, 244, 224, 
    123, 151, 194, 190, 161, 170, 219, 227, 283, 275, 121, 177, 140, 
    164, 353, 185, 230, 293, 320, 256, 37, 4, 321, 322, 267, 327, 
    273, 206, 241, 169, 110, 147, 323, 242, 168, 24, 301, 19, 204, 
    69, 297, 362, 281, 257, 334, 108, 73, 325, 326, 331, 268, 207, 
    272, 274, 348, 39, 61, 243, 324, 189, 134, 142, 181, 23, 99, 
    356, 247, 276, 205, 27, 72, 221, 339, 149, 43, 54, 103, 238, 
    192, 143, 84, 114, 154, 9, 32, 75, 178, 291, 158, 237, 328, 
    292, 81, 85, 264, 337, 97, 68, 31, 44, 234, 352, 302, 193, 
    82, 52, 45, 60, 355, 132, 83, 258, 233, 223, 277, 288, 340, 
    342, 236, 232, 104, 126, 179, 162, 152, 173, 222, 235, 278, 269, 
    14, 171, 138, 163, 367, 102, 119, 309, 308, 129, 42, 200, 280, 
    93, 55, 62, 47, 213, 175, 6, 26, 116, 66, 165, 128, 88, 
    29, 307, 306, 208, 167, 279, 199, 130, 191, 5, 25, 131, 67, 
    87, 46, 370, 172, 259, 166, 378, 76, 3, 153, 148, 218, 262, 
    95, 120, 144, 125, 260, 330, 251, 209, 89, 91, 118, 2, 101, 
    48, 212, 186, 263, 217, 77, 65, 28, 78, 329, 261, 176, 150, 
    349, 117, 90, 34, 365, 298, 296, 228, 225, 216, 198, 311, 300, 
    304, 310, 317, 315, 109, 314, 1, 86, 299, 295, 229, 226, 343, 
    364, 63, 133, 303, 305, 318, 316, 366, 157, 156, 49, 359, 290, 
    188, 248, 174, 245, 203, 336, 215, 319, 250, 124, 135, 201, 33, 
    187, 289, 220, 350, 202, 246, 214, 338, 249, 335, 363, 184, 136, 
    41, 351, 80, 53, 145, 313, 183, 287, 211, 271, 96, 107, 74, 
    127, 16, 22, 312, 146, 286, 182, 270, 210, 346, 40, 15, 266, 
    347, 7, 17, 195, 70, 51, 113, 100, 180, 50, 122, 18, 11, 
    141, 94, 105, 159, 357, 368, 92, 64, 358, 196, 253, 79, 21, 
    59, 13, 111, 10, 252, 197, 56, 8, 361, 58, 57, 30, 371, 
    254, 333, 35, 20, 139, 155, 332, 255, 360, 38, 71, 115, 354, 
    112, 12, 137, 160, 369, 36, 98, 106, 372, 373, 374, 375, 376, 377]) 

我的每個功能都有一個功能名稱（不只是一個數字）。我可以查看索引並將每個數字映射到其各自的功能名稱，但它有378個功能有點繁瑣。有沒有一種方法可以簡單地列出功能名稱而不是列索引號？

謝謝。

Answer 1

假設你使用的是熊貓，你可能只是這樣做：

for col_num in selector.ranking_ : 
    print(yourDataFrame.columns[col_num]) 

其他選項是很難說，除非我們不知道你selector是什麼。 如果您有例如from sklearn.feature_selection import SelectKBest 你可以做s.th.如：

mask = selector.get_support() #list of booleans 
    new_features = [] #becomes the list of your K best features in the following loop 

    for bool, feature in zip(mask, feature_names): 
     if bool: 
      new_features.append(feature)