import tensorflow as tf

from tensorflow.examples.tutorials.mnist import input_data

from tensorflow.contrib.tensorboard.plugins import projector

#载入数据集

mnist = input_data.read_data_sets("MNIST_data/",one_hot=True)

#运行次数

max_steps = 1001

#图片数量

image_num = 3000

#文件路径

DIR = "E:/Github/TensorFlow/trunk/Test/"

#定义会话

sess = tf.Session()

#载入图片

embedding = tf.Variable(tf.stack(mnist.test.images[:image_num]), trainable=False, name='embedding')

#参数概要

def variable_summaries(var):

    with tf.name_scope('summaries'):

        mean = tf.reduce_mean(var)

        tf.summary.scalar('mean', mean)#平均值

        with tf.name_scope('stddev'):

            stddev = tf.sqrt(tf.reduce_mean(tf.square(var - mean)))

        tf.summary.scalar('stddev', stddev)#标准差

        tf.summary.scalar('max', tf.reduce_max(var))#最大值

        tf.summary.scalar('min', tf.reduce_min(var))#最小值

        tf.summary.histogram('histogram', var)#直方图

#命名空间

with tf.name_scope('input'):

    #这里的none表示第一个维度可以是任意的长度

    x = tf.placeholder(tf.float32,[None,784],name='x-input')

    #正确的标签

    y = tf.placeholder(tf.float32,[None,10],name='y-input')

#显示图片

with tf.name_scope('input_reshape'):

    image_shaped_input = tf.reshape(x, [-1, 28, 28, 1])

    tf.summary.image('input', image_shaped_input, 10)

with tf.name_scope('layer'):

    #创建一个简单神经网络

    with tf.name_scope('weights'):

        W = tf.Variable(tf.zeros([784,10]),name='W')

        variable_summaries(W)

    with tf.name_scope('biases'):

        b = tf.Variable(tf.zeros([10]),name='b')

        variable_summaries(b)

    with tf.name_scope('wx_plus_b'):

        wx_plus_b = tf.matmul(x,W) + b

    with tf.name_scope('softmax'):

        prediction = tf.nn.softmax(wx_plus_b)

with tf.name_scope('loss'):

    #交叉熵代价函数

    loss = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(labels=y,logits=prediction))

    tf.summary.scalar('loss',loss)

with tf.name_scope('train'):

    #使用梯度下降法

    train_step = tf.train.GradientDescentOptimizer(0.5).minimize(loss)

#初始化变量

sess.run(tf.global_variables_initializer())

with tf.name_scope('accuracy'):

    with tf.name_scope('correct_prediction'):

        #结果存放在一个布尔型列表中

        correct_prediction = tf.equal(tf.argmax(y,1),tf.argmax(prediction,1))#argmax返回一维张量中最大的值所在的位置

    with tf.name_scope('accuracy'):

        #求准确率

        accuracy = tf.reduce_mean(tf.cast(correct_prediction,tf.float32))#把correct_prediction变为float32类型

        tf.summary.scalar('accuracy',accuracy)

#产生metadata文件

if tf.gfile.Exists(DIR + 'projector/projector/metadata.tsv'):

    tf.gfile.DeleteRecursively(DIR + 'projector/projector/metadata.tsv')

with open(DIR + 'projector/projector/metadata.tsv', 'w') as f:

    labels = sess.run(tf.argmax(mnist.test.labels[:],1))

    for i in range(image_num):

        f.write(str(labels[i]) + '\n')        

#合并所有的summary

merged = tf.summary.merge_all()   

projector_writer = tf.summary.FileWriter(DIR + 'projector/projector',sess.graph)

saver = tf.train.Saver()

config = projector.ProjectorConfig()

embed = config.embeddings.add()

embed.tensor_name = embedding.name

embed.metadata_path = DIR + 'projector/projector/metadata.tsv'

embed.sprite.image_path = DIR + 'projector/data/mnist_10k_sprite.png'

embed.sprite.single_image_dim.extend([28,28])

projector.visualize_embeddings(projector_writer,config)

for i in range(max_steps):

    #每个批次100个样本

    batch_xs,batch_ys = mnist.train.next_batch(100)

    run_options = tf.RunOptions(trace_level=tf.RunOptions.FULL_TRACE)

    run_metadata = tf.RunMetadata()

    sess.run(train_step,feed_dict={x:batch_xs,y:batch_ys},options=run_options,run_metadata=run_metadata)

    summary = sess.run(merged,feed_dict={x:batch_xs,y:batch_ys},options=run_options,run_metadata=run_metadata)

    projector_writer.add_run_metadata(run_metadata, 'step%03d' % i)

    projector_writer.add_summary(summary, i)

    if i%100 == 0:

        acc = sess.run(accuracy,feed_dict={x:mnist.test.images,y:mnist.test.labels})

        print ("Iter " + str(i) + ", Testing Accuracy= " + str(acc))

saver.save(sess, DIR + 'projector/projector/a_model.ckpt', global_step=max_steps)

projector_writer.close()

sess.close()