无涯教程-TensorFlow - 梯度下降优化

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梯度下降优化被认为是数据科学中的重要概念,考虑以下所示的步骤,以了解梯度下降优化的实现-

第1步    -  包括必要的模块以及x和y变量的声明,通过它们无涯教程将定义梯度下降优化。

import tensorflow as tf

x = tf.Variable(2, name = x, dtype = tf.float32) log_x = tf.log(x) log_x_squared = tf.square(log_x)

optimizer = tf.train.GradientDescentOptimizer(0.5) train = optimizer.minimize(log_x_squared)

第2步    -  初始化必要的变量,并调用优化器以使用相应的函数进行定义和调用。

init = tf.initialize_all_variables()

def optimize(): with tf.Session() as session: session.run(init) print("starting at", "x:", session.run(x), "log(x)^2:", session.run(log_x_squared))

  </span><span class="kwd">for</span><span class="pln"> step </span><span class="kwd">in</span><span class="pln"> range</span><span class="pun">(</span><span class="lit">10</span><span class="pun">):</span><span class="pln">
     session</span><span class="pun">.</span><span class="pln">run</span><span class="pun">(</span><span class="pln">train</span><span class="pun">)</span><span class="pln">
     </span><span class="kwd">print</span><span class="pun">(</span><span class="str">"step"</span><span class="pun">,</span><span class="pln"> step</span><span class="pun">,</span><span class="pln"> </span><span class="str">"x:"</span><span class="pun">,</span><span class="pln"> session</span><span class="pun">.</span><span class="pln">run</span><span class="pun">(</span><span class="pln">x</span><span class="pun">),</span><span class="pln"> </span><span class="str">"log(x)^2:"</span><span class="pun">,</span><span class="pln"> session</span><span class="pun">.</span><span class="pln">run</span><span class="pun">(</span><span class="pln">log_x_squared</span><span class="pun">))</span><span class="pln">

optimize()

上面的代码行生成输出,如下面的屏幕快照所示-

Initialize Variables

参考链接

www.learnfk.com/tensorflow/…