本文基於TensorFlow官網How-Tos的Visualizing Learning和Graph Visualization寫成。git
TensorBoard是TensorFlow自帶的一個可視化工具。本文在學習筆記(4)的基礎上修改少許代碼,以探索TensorBoard的使用方法。segmentfault
# -*- coding=utf-8 -*- # @author: 陳水平 # @date: 2017-02-09 # @description: implement a softmax regression model upon MNIST handwritten digits # @ref: http://yann.lecun.com/exdb/mnist/ import gzip import struct import numpy as np from sklearn.linear_model import LogisticRegression from sklearn import preprocessing from sklearn.metrics import accuracy_score import tensorflow as tf # MNIST data is stored in binary format, # and we transform them into numpy ndarray objects by the following two utility functions def read_image(file_name): with gzip.open(file_name, 'rb') as f: buf = f.read() index = 0 magic, images, rows, columns = struct.unpack_from('>IIII' , buf , index) index += struct.calcsize('>IIII') image_size = '>' + str(images*rows*columns) + 'B' ims = struct.unpack_from(image_size, buf, index) im_array = np.array(ims).reshape(images, rows, columns) return im_array def read_label(file_name): with gzip.open(file_name, 'rb') as f: buf = f.read() index = 0 magic, labels = struct.unpack_from('>II', buf, index) index += struct.calcsize('>II') label_size = '>' + str(labels) + 'B' labels = struct.unpack_from(label_size, buf, index) label_array = np.array(labels) return label_array print "Start processing MNIST handwritten digits data..." train_x_data = read_image("MNIST_data/train-images-idx3-ubyte.gz") train_x_data = train_x_data.reshape(train_x_data.shape[0], -1).astype(np.float32) train_y_data = read_label("MNIST_data/train-labels-idx1-ubyte.gz") test_x_data = read_image("MNIST_data/t10k-images-idx3-ubyte.gz") test_x_data = test_x_data.reshape(test_x_data.shape[0], -1).astype(np.float32) test_y_data = read_label("MNIST_data/t10k-labels-idx1-ubyte.gz") train_x_minmax = train_x_data / 255.0 test_x_minmax = test_x_data / 255.0 # Of course you can also use the utility function to read in MNIST provided by tensorflow # from tensorflow.examples.tutorials.mnist import input_data # mnist = input_data.read_data_sets("MNIST_data/", one_hot=False) # train_x_minmax = mnist.train.images # train_y_data = mnist.train.labels # test_x_minmax = mnist.test.images # test_y_data = mnist.test.labels # We evaluate the softmax regression model by sklearn first eval_sklearn = False if eval_sklearn: print "Start evaluating softmax regression model by sklearn..." reg = LogisticRegression(solver="lbfgs", multi_class="multinomial") reg.fit(train_x_minmax, train_y_data) np.savetxt('coef_softmax_sklearn.txt', reg.coef_, fmt='%.6f') # Save coefficients to a text file test_y_predict = reg.predict(test_x_minmax) print "Accuracy of test set: %f" % accuracy_score(test_y_data, test_y_predict) eval_tensorflow = True batch_gradient = False def variable_summaries(var): with tf.name_scope('summaries'): mean = tf.reduce_mean(var) tf.summary.scalar('mean', mean) stddev = tf.sqrt(tf.reduce_mean(tf.square(var - mean))) tf.summary.scalar('stddev', stddev) tf.summary.scalar('max', tf.reduce_max(var)) tf.summary.scalar('min', tf.reduce_min(var)) tf.summary.histogram('histogram', var) if eval_tensorflow: print "Start evaluating softmax regression model by tensorflow..." # reformat y into one-hot encoding style lb = preprocessing.LabelBinarizer() lb.fit(train_y_data) train_y_data_trans = lb.transform(train_y_data) test_y_data_trans = lb.transform(test_y_data) x = tf.placeholder(tf.float32, [None, 784]) with tf.name_scope('weights'): W = tf.Variable(tf.zeros([784, 10])) variable_summaries(W) with tf.name_scope('biases'): b = tf.Variable(tf.zeros([10])) variable_summaries(b) with tf.name_scope('Wx_plus_b'): V = tf.matmul(x, W) + b tf.summary.histogram('pre_activations', V) with tf.name_scope('softmax'): y = tf.nn.softmax(V) tf.summary.histogram('activations', y) y_ = tf.placeholder(tf.float32, [None, 10]) with tf.name_scope('cross_entropy'): loss = tf.reduce_mean(-tf.reduce_sum(y_ * tf.log(y), reduction_indices=[1])) tf.summary.scalar('cross_entropy', loss) with tf.name_scope('train'): optimizer = tf.train.GradientDescentOptimizer(0.5) train = optimizer.minimize(loss) with tf.name_scope('evaluate'): with tf.name_scope('correct_prediction'): correct_prediction = tf.equal(tf.argmax(y, 1), tf.argmax(y_, 1)) with tf.name_scope('accuracy'): accuracy = tf.reduce_mean(tf.cast(correct_prediction, tf.float32)) tf.summary.scalar('accuracy', accuracy) init = tf.global_variables_initializer() sess = tf.Session() sess.run(init) merged = tf.summary.merge_all() train_writer = tf.summary.FileWriter('log/train', sess.graph) test_writer = tf.summary.FileWriter('log/test') if batch_gradient: for step in range(300): sess.run(train, feed_dict={x: train_x_minmax, y_: train_y_data_trans}) if step % 10 == 0: print "Batch Gradient Descent processing step %d" % step print "Finally we got the estimated results, take such a long time..." else: for step in range(1000): if step % 10 == 0: summary, acc = sess.run([merged, accuracy], feed_dict={x: test_x_minmax, y_: test_y_data_trans}) test_writer.add_summary(summary, step) print "Stochastic Gradient Descent processing step %d accuracy=%.2f" % (step, acc) else: sample_index = np.random.choice(train_x_minmax.shape[0], 100) batch_xs = train_x_minmax[sample_index, :] batch_ys = train_y_data_trans[sample_index, :] summary, _ = sess.run([merged, train], feed_dict={x: batch_xs, y_: batch_ys}) train_writer.add_summary(summary, step) np.savetxt('coef_softmax_tf.txt', np.transpose(sess.run(W)), fmt='%.6f') # Save coefficients to a text file print "Accuracy of test set: %f" % sess.run(accuracy, feed_dict={x: test_x_minmax, y_: test_y_data_trans})
主要修改點有:dom
Summary
:全部須要在TensorBoard上展現的統計結果。ide
tf.name_scope()
:爲Graph中的Tensor添加層級,TensorBoard會按照代碼指定的層級進行展現,初始狀態下只繪製最高層級的效果,點擊後可展開層級看到下一層的細節。工具
tf.summary.scalar()
:添加標量統計結果。學習
tf.summary.histogram()
:添加任意shape的Tensor,統計這個Tensor的取值分佈。lua
tf.summary.merge_all()
:添加一個操做,表明執行全部summary操做,這樣能夠避免人工執行每個summary op。spa
tf.summary.FileWrite
:用於將Summary寫入磁盤,須要制定存儲路徑logdir,若是傳遞了Graph對象,則在Graph Visualization會顯示Tensor Shape Information。執行summary op後,將返回結果傳遞給add_summary()
方法便可。scala
首先是Distribution,顯示取值範圍:code
更細節的取值機率信息在Historgram裏,以下:
雙擊train後,可查看下一層級的詳細信息: