{"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":208,"pdf_page":224,"physical_index":224,"physical_index_base":0,"printed_page_status":"recognized","page_sha256":"175ef7dbe80388395bfdde88ffaacf8dad1b99a51b2b6bdf7d5cdbfc4c16945d"},"chapter":"第7章","content":"要使用卷积神经网络，我们还需要进一步将X的每一条记录展开成28×28×1的形式(图片为黑白色，所以只有1个channel）。这时X变成了四维（样本数为第一个维度，每一个样本是28×28×1的三维数据）。\n\n然后对输入数据X进行标准化处理。这里输入数据的数字全部处于0\\~255之间，因此我们将其除以255，使数字落在0\\~1之间：\n\n除了X之外，这里还需要对标签值Y进行处理，Y的范围为数字0\\~9，属于多分类，需要对其进行独热编码（one-hot encoding）。这是将多类别数值转化为0或1数值的操作，方便处理。读者可以发现，经过这个处理后，长度为42000的向量ytrain变成了42000×10的矩阵（称为大写的Ytrain）。原先y的每个数值被对应为一个维度为10的向量。Y等于几，这个向量的第几个维度就等于1，其他均为0。\n\n人工智能与大数据技术导论\n\n208","previous_page":207,"next_page":209}