說明

NLC服務使用機器學習算法返回短文本輸入的匹配預定義類。創建和訓練一個分類器，將預定義分類與示例文本連接起來，以便服務可以將這些分類器可以對新的輸入進行分類

認證方式

使用HTTP Basic Authentication方式認證。 即用戶名/密碼方式

創建一個分類器

CURL命令

curl -u "USERNAME":"PASSWORD"  ^
-F training_data=@weather_data_train.csv  ^
-F training_metadata="{\"language\":\"en\",\"name\":\"atp-weather\"}"  ^
"https://gateway.watsonplatform.net/natural-language-classifier/api/v1/classifiers"

返回值

{
  "classifier_id" : "359f3fx202-nlc-223328",
  "name" : "atp-weather",
  "language" : "en",
  "created" : "2017-07-25T03:20:16.451Z",
  "url" : "https://gateway.watsonplatform.net/natural-language-classifier/api/v1/classifiers/359f3fx202-nlc-223328",
  "status" : "Training",
  "status_description" : "The classifier instance is in its training phase, not yet ready to accept classify requests"
}

** 注意此時分類器的狀態為訓練中 暫時還不能使用。我們可以通過命令查看分類器狀態**

查看分類器列表

CURL命令

curl -u "USERNAME":"PASSWORD" ^
"https://gateway.watsonplatform.net/natural-language-classifier/api/v1/classifiers"

返回值

{
  "classifiers" : [ {
    "classifier_id" : "359f3fx202-nlc-223328",
    "url" : "https://gateway.watsonplatform.net/natural-language-classifier/api/v1/classifiers/359f3fx202-nlc-223328",
    "name" : "atp-weather",
    "language" : "en",
    "created" : "2017-07-25T03:20:16.451Z"
  } ]
}

查看分類器信息

CURL命令

curl -u "USERNAME":"PASSWORD"  ^
"https://gateway.watsonplatform.net/natural-language-classifier/api/v1/classifiers/359f3fx202-nlc-223328"

返回值

{
  "classifier_id" : "359f3fx202-nlc-223328",
  "name" : "atp-weather",
  "language" : "en",
  "created" : "2017-07-25T03:20:16.451Z",
  "url" : "https://gateway.watsonplatform.net/natural-language-classifier/api/v1/classifiers/359f3fx202-nlc-223328",
  "status" : "Available",
  "status_description" : "The classifier instance is now available and is ready to take classifier requests."
}

分類器有如下五種狀態

• 1 Non Existent : 不存在
• 2 Training : 訓練中
• 3 Failed：失敗
• 4 Available：有效
• 5 Unavailable：無效

使用分類器進行分類

CURL命令

• Get方法分類 How how will it be today?

curl -G -u "USERNAME":"PASSWORD" ^
"https://gateway.watsonplatform.net/natural-language-classifier/api/v1/classifiers/359f3fx202-nlc-223328/classify?text=How%20hot%20will%20it%20be%20today%3F"

• Post方法分類 How how will it be today?

curl -X POST -u "USERNAME":"PASSWORD" ^
-H "Content-Type:application/json" ^
-d "{\"text\":\"How hot will it be today?\"}" ^
"https://gateway.watsonplatform.net/natural-language-classifier/api/v1/classifiers/359f3fx202-nlc-223328/classify"

返回值

{
  "classifier_id" : "359f3fx202-nlc-223328",
  "url" : "https://gateway.watsonplatform.net/natural-language-classifier/api/v1/classifiers/359f3fx202-nlc-223328",
  "text" : "How hot will it be today?",
  "top_class" : "temperature",
  "classes" : [ {
    "class_name" : "temperature",
    "confidence" : 0.9929586035651006
  }, {
    "class_name" : "conditions",
    "confidence" : 0.007041396434899482
  } ]
}

使用分類器訓練數據中未包含的詞匯（sleet 為雨夾雪）
特意使用了temperature分類中包含的句式 how xxx it is today?
分類器還是準確將其分到condition類中了。

curl -X POST -u "username":"password" ^
-H "Content-Type:application/json" ^
-d "{\"text\":\"How sleet will it be today?\"}" ^
"https://gateway.watsonplatform.net/natural-language-classifier/api/v1/classifiers/359f3fx202-nlc-223328/classify"

返回值

{
  "classifier_id" : "359f3fx202-nlc-223328",
  "url" : "https://gateway.watsonplatform.net/natural-language-classifier/api/v1/classifiers/359f3fx202-nlc-223328",
  "text" : "How sleet will it be today?",
  "top_class" : "conditions",
  "classes" : [ {
    "class_name" : "conditions",
    "confidence" : 0.89688785244637
  }, {
    "class_name" : "temperature",
    "confidence" : 0.10311214755363002
  } ]
}

使用分類器完全無關的詞匯 it is atp's notebook?
分類結果非常不理想 temperature類的置信度竟然高達82%

curl -X POST -u "74e23665-dfea-4bd6-ad80-3e9b4a7f7604":"RxFKejjwlUcA" ^
-H "Content-Type:application/json" ^
-d "{\"text\":\"it is atp's notebook?\"}" ^
"https://gateway.watsonplatform.net/natural-language-classifier/api/v1/classifiers/359f3fx202-nlc-223328/classify"

返回值

{
  "classifier_id" : "359f3fx202-nlc-223328",
  "url" : "https://gateway.watsonplatform.net/natural-language-classifier/api/v1/classifiers/359f3fx202-nlc-223328",
  "text" : "it is atp's notebook?",
  "top_class" : "temperature",
  "classes" : [ {
    "class_name" : "temperature",
    "confidence" : 0.8255246180698945
  }, {
    "class_name" : "conditions",
    "confidence" : 0.1744753819301055
  } ]
}

刪除一個分類器

CURL命令

curl -X DELETE -u "{username}":"{password}" 
"https://gateway.watsonplatform.net/natural-language-classifier/api/v1/classifiers/10D41B-nlc-1"

要點

• 置信度值表示為百分比，值越大表示置信度越高。響應最多包含 10 個類。
• 如果培訓數據中的類少于10個，那么所有置信度值的和為 100%。例如只定義了兩個類，就只能返回兩個類。
• 其中一個樣本問題包含未對分類器進行培訓的詞語（“foggy”）。您無須執行額外工作來識別這些“缺少”的詞語，分類器對于這些詞語就能獲得不錯的分數。請嘗試使用包含培訓數據中沒有的詞（例如，“sleet”或“storm”）的其他問題。

課題

• 1 支持語言 en之外還包含？
• 2 訓練數據文本的格式 csv固定？ csv的format也是固定？
• 3 分類器建成以后是否可以追加training數據