{"resolved":true,"match_type":"uuid","source_type":"original_book","book_id":"cd4f7678-cd9b-4971-bde0-e9ad46a6cc71","title":"人工智能与大数据技术导论","author":null,"edition":null,"publisher":null,"year":null,"isbn":"9787302517986","requested_by":"printed_page","book":{"source_type":"original_book","book_id":"cd4f7678-cd9b-4971-bde0-e9ad46a6cc71","id":"cd4f7678-cd9b-4971-bde0-e9ad46a6cc71","uuid":"cd4f7678-cd9b-4971-bde0-e9ad46a6cc71","title":"人工智能与大数据技术导论","normalized_title":"人工智能与大数据技术导论","author":null,"edition":null,"publisher":null,"year":null,"isbn":"9787302517986","isbns":["9787302517986"],"parsed":true,"ai_readable":true,"document_type":"book","page_count":490,"navigation_url":"https://workshop.closeclaw.top/ai/book/cd4f7678-cd9b-4971-bde0-e9ad46a6cc71","title_url":"https://workshop.closeclaw.top/ai/title/%E4%BA%BA%E5%B7%A5%E6%99%BA%E8%83%BD%E4%B8%8E%E5%A4%A7%E6%95%B0%E6%8D%AE%E6%8A%80%E6%9C%AF%E5%AF%BC%E8%AE%BA","fixed_page_url_template":"https://workshop.closeclaw.top/ai/book/cd4f7678-cd9b-4971-bde0-e9ad46a6cc71/page/{printed_page}","path_api_url_template":"https://workshop.closeclaw.top/api/ai/book/cd4f7678-cd9b-4971-bde0-e9ad46a6cc71/page/{printed_page}","read_url":"https://workshop.closeclaw.top/api/ai/read/cd4f7678-cd9b-4971-bde0-e9ad46a6cc71","page_url":"https://workshop.closeclaw.top/api/ai/books/cd4f7678-cd9b-4971-bde0-e9ad46a6cc71/page","search_url":"https://workshop.closeclaw.top/api/ai/books/cd4f7678-cd9b-4971-bde0-e9ad46a6cc71/search"},"page":{"printed_page":145,"pdf_page":161,"physical_index":161,"physical_index_base":0,"printed_page_status":"recognized","page_sha256":"bf4b79c0f539e6c8a10cfced1722eca66d3e14fe1097b0969e1a6943f09872ad"},"chapter":"第4章","content":"4.3.3 特征工程\n\n特征工程（FeatureEngineering）又称特征提取，是机器学习建模之前的一个重要步骤。前文提到，机器学习的本质是要找从x到y的映射，我们最终的目标是输出y。如果x“不给力”的话，后面的努力往往会成为徒劳。特征工程就是从原始数据中找到合适的特征集x的过程。\n\n在很多机器学习任务中，特征工程是最重要，也是最耗时的环节，其重要性远远超过建模和训练。然而这个过程最容易被初学者忽视。特征工程是漫长而艰苦的过程。在Kaggle数据科学竞赛中，选手们平均花在构建特征集的时间在70%以上。一个好的特征集通常能战胜一个好的模型或者算法。\n\n第4章 机器学习概述\n\n145","previous_page":144,"next_page":null}