{"id":10120,"date":"2018-01-17T00:34:57","date_gmt":"2018-01-17T05:34:57","guid":{"rendered":"httpss:\/\/www.powenko.com\/wordpress\/?p=10120"},"modified":"2018-01-17T00:34:57","modified_gmt":"2018-01-17T05:34:57","slug":"08-placeholders-%e6%9a%ab%e5%ad%98%e8%ae%8a%e6%95%b8","status":"publish","type":"post","link":"https:\/\/www.powenko.com\/wordpress\/?p=10120","title":{"rendered":"08 placeholders \u66ab\u5b58\u8b8a\u6578"},"content":{"rendered":"

Placeholder \u53ef\u4ee5\u6307\u5b9a<\/span><\/span><\/strong>\u53c3\u6578\u5316\u4f86\u63a5\u53d7\u5916\u90e8\u8f38\u5165\u3002 <\/span><\/p>\n

a = tf.placeholder\uff08<\/span><\/span>tf.float32\uff09<\/span><\/span><\/p>\n

b = tf.placeholder\uff08<\/span><\/span>tf.float32\uff09<\/span><\/span><\/p>\n

adder_node = a + b \uff03 \u51fd\u6578\u7684\u8a2d\u5b9a\uff0c\u4e5f\u53ef\u4ee5\u5beb\u6210 <\/span><\/span>adder_node = tf.add(a, b)<\/p>\n

\u524d\u9762\u7684\u4e09\u884c\u6709\u9ede\u50cf\u51fd\u6578\u7684\u8a2d\u5b9a\uff0c\u5176\u4e2d\u5b9a\u7fa9\u5169\u500b\u8f38\u5165\u53c3\u6578\uff08<\/span><\/span><\/span>a<\/span><\/span>\u548c<\/span><\/span><\/span>b<\/span><\/span>\uff09\uff0c\u7136\u5f8c\u5c0d\u5b83\u5011\u9032\u884c\u64cd\u4f5c\u3002 \u6211\u5011\u53ef\u4ee5\u901a\u904e\u4f7f\u7528<\/span><\/span><\/span>run<\/span><\/span>\u65b9\u6cd5\u7684\u5c07\u53c3\u6578\u8f38\u5165\u5177\u9ad4\u503c\u3002<\/span><\/span><\/span><\/p>\n

\u7bc4\u4f8b\u7a0b\u5f0f<\/span><\/span><\/span>05_placeholder.py<\/span><\/span><\/p>\n

    \n
  1. import tensorflow as tf<\/li>\n
  2. sess = tf.Session()<\/li>\n
  3. a = tf.placeholder(tf.float32) # \u8b8a\u6578<\/span><\/span>a \u70ba <\/span><\/span>float32<\/li>\n
  4. b = tf.placeholder(tf.float32) # \u8b8a\u6578<\/span><\/span>b \u70ba <\/span><\/span>float32<\/li>\n
  5. adder_node = tf.add(a, b) # \u5b9a\u7fa9\u76f8\u52a0\u51fd\u6578<\/span><\/span><\/li>\n
  6. adder_node = a + b # \u4e5f\u53ef\u4ee5\u9019\u6a23\u5beb<\/span><\/span><\/li>\n
  7. print(sess.run(adder_node, {a: 3, b: 4.5})) # \u7d50\u679c <\/span><\/span>7.5<\/li>\n
  8. print(sess.run(adder_node, {a: [1, 3], b: [2, 4]})) # \u7d50\u679c<\/span><\/span>[ 3. 7.]<\/li>\n<\/ol>\n

    \u5716<\/span><\/span><\/span>6 <\/span><\/span>\u57f7\u884c\u7d50\u679c<\/span><\/span><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

    Placeholder \u53ef\u4ee5\u6307\u5b9a\u53c3\u6578\u5316\u4f86\u63a5\u53d7\u5916\u90e8\u8f38\u5165\u3002 a = tf.placeholder\uff08tf.float […]<\/p>\n","protected":false},"author":1,"featured_media":10108,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[360],"tags":[],"class_list":["post-10120","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-ch02-"],"_links":{"self":[{"href":"https:\/\/www.powenko.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/10120"}],"collection":[{"href":"https:\/\/www.powenko.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.powenko.com\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.powenko.com\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.powenko.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10120"}],"version-history":[{"count":1,"href":"https:\/\/www.powenko.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/10120\/revisions"}],"predecessor-version":[{"id":10121,"href":"https:\/\/www.powenko.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/10120\/revisions\/10121"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.powenko.com\/wordpress\/index.php?rest_route=\/wp\/v2\/media\/10108"}],"wp:attachment":[{"href":"https:\/\/www.powenko.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10120"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.powenko.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10120"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.powenko.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10120"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}