{"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":249,"pdf_page":265,"physical_index":265,"physical_index_base":0,"printed_page_status":"recognized","page_sha256":"34474aa0b30ee547fd3aee7f517d8c6f91c0badb4ce82965999430573ea59cba"},"chapter":"第8章","content":"特征工程\n\n在现实世界中，我们拿到的数据可能是数据库记录、文本文件或其他形式。我们必须从各种各样的数据源中提取数据，然后根据这些数据创建特征向量。从原始数据中提取特征的过程称为特征工程。从事机器学习的专业人员将花费超过一半的时间在特征工程方面。\n\n8.4.1 数值型数据\n\n接下来，我们了解一下特征工程是如何发生的，也就是说，怎么从原始数据(RawData)中提取特征。如果某个记录本来就是一个数字，例如房子的房间数量，我们可以直接把这个值对应到一个特征向量（feature vector）中，如图8-46所示。\n\n249","previous_page":248,"next_page":250}