TensorFlow深度学习另一种程序风格实现卷积神经网络
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2022-06-19 13:45:10
import tensorflow as tfimport numpy as npimport input_datamnist = input_data.read_data_sets('data/',...
import tensorflow as tf import numpy as np import input_data mnist = input_data.read_data_sets('data/', one_hot=true) print("mnist ready") n_input = 784 # 28*28的灰度图,像素个数784 n_output = 10 # 是10分类问题 # 权重项 weights = { # conv1,参数[3, 3, 1, 32]分别指定了filter的h、w、所连接输入的维度、filter的个数即产生特征图个数 'wc1': tf.variable(tf.random_normal([3, 3, 1, 32], stddev=0.1)), # conv2,这里参数3,3同上,32是当前连接的深度是32,即前面特征图的个数,64为输出的特征图的个数 'wc2': tf.variable(tf.random_normal([3, 3, 32, 64], stddev=0.1)), # fc1,将特征图转换为向量,1024由自己定义 'wd1': tf.variable(tf.random_normal([7*7*64, 1024], stddev=0.1)), # fc2,做10分类任务,前面连1024,输出10分类 'wd2': tf.variable(tf.random_normal([1024, n_output], stddev=0.1)) } """ 特征图大小计算: f_w = (w-f+2*pad)/s + 1 = (28-3+2*1)/1 + 1 = 28 # 说明经过卷积层并没有改变图片的大小 f_h = (h-f+2*pad)/s + 1 = (28-3+2*1)/1 + 1 = 28 # 特征图的大小是经过池化层后改变的 第一次pooling后28*28变为14*14 第二次pooling后14*14变为7*7,即最终是一个7*7*64的特征图 """ # 偏置项 biases = { 'bc1': tf.variable(tf.random_normal([32], stddev=0.1)), # conv1,对应32个特征图 'bc2': tf.variable(tf.random_normal([64], stddev=0.1)), # conv2,对应64个特征图 'bd1': tf.variable(tf.random_normal([1024], stddev=0.1)), # fc1,对应1024个向量 'bd2': tf.variable(tf.random_normal([n_output], stddev=0.1)) # fc2,对应10个输出 } def conv_basic(_input, _w, _b, _keep_prob): # input # 对图像做预处理,转换为tf支持的格式,即[n, h, w, c],-1是确定好其它3维后,让tf去推断剩下的1维 _input_r = tf.reshape(_input, shape=[-1, 28, 28, 1]) # conv layer 1 _conv1 = tf.nn.conv2d(_input_r, _w['wc1'], strides=[1, 1, 1, 1], padding='same') # [1, 1, 1, 1]分别代表batch_size、h、w、c的stride # padding有两种选择:'same'(窗口滑动时,像素不够会自动补0)或'valid'(不够就跳过)两种选择 _conv1 = tf.nn.relu(tf.nn.bias_add(_conv1, _b['bc1'])) # 卷积层后连激活函数 # 最大值池化,[1, 2, 2, 1]其中1,1对应batch_size和channel,2,2对应2*2的池化 _pool1 = tf.nn.max_pool(_conv1, ksize=[1, 2, 2, 1], strides=[1, 2, 2, 1], padding='same') # 随机杀死一些神经元,_keepratio为保留神经元比例,如0.6 _pool_dr1 = tf.nn.dropout(_pool1, _keep_prob) # conv layer 2 _conv2 = tf.nn.conv2d(_pool_dr1, _w['wc2'], strides=[1, 1, 1, 1], padding='same') _conv2 = tf.nn.relu(tf.nn.bias_add(_conv2, _b['bc2'])) _pool2 = tf.nn.max_pool(_conv2, ksize=[1, 2, 2, 1], strides=[1, 2, 2, 1], padding='same') _pool_dr2 = tf.nn.dropout(_pool2, _keep_prob) # dropout # vectorize向量化 # 定义全连接层的输入,把pool2的输出做一个reshape,变为向量的形式 _densel = tf.reshape(_pool_dr2, [-1, _w['wd1'].get_shape().as_list()[0]]) # fully connected layer 1 _fc1 = tf.nn.relu(tf.add(tf.matmul(_densel, _w['wd1']), _b['bd1'])) # w*x+b,再通过relu _fc_dr1 = tf.nn.dropout(_fc1, _keep_prob) # dropout # fully connected layer 2 _out = tf.add(tf.matmul(_fc_dr1, _w['wd2']), _b['bd2']) # w*x+b,得到结果 # return out = {'input_r': _input_r, 'conv1': _conv1, 'pool1': _pool1, 'pool_dr1': _pool_dr1, 'conv2': _conv2, 'pool2': _pool2, 'pool_dr2': _pool_dr2, 'densel': _densel, 'fc1': _fc1, 'fc_dr1': _fc_dr1, 'out': _out } return out print("cnn ready") x = tf.placeholder(tf.float32, [none, n_input]) # 用placeholder先占地方,样本个数不确定为none y = tf.placeholder(tf.float32, [none, n_output]) # 用placeholder先占地方,样本个数不确定为none keep_prob = tf.placeholder(tf.float32) _pred = conv_basic(x, weights, biases, keep_prob)['out'] # 前向传播的预测值 cost = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(_pred, y)) # 交叉熵损失函数 optm = tf.train.adamoptimizer(0.001).minimize(cost) # 梯度下降优化器 _corr = tf.equal(tf.argmax(_pred, 1), tf.argmax(y, 1)) # 对比预测值索引和实际label索引,相同返回true,不同返回false accr = tf.reduce_mean(tf.cast(_corr, tf.float32)) # 将true或false转换为1或0,并对所有的判断结果求均值 init = tf.global_variables_initializer() print("functions ready") # 上面神经网络结构定义好之后,下面定义一些超参数 training_epochs = 1000 # 所有样本迭代1000次 batch_size = 100 # 每进行一次迭代选择100个样本 display_step = 1 # launch the graph sess = tf.session() # 定义一个session sess.run(init) # 在sess里run一下初始化操作 # optimize for epoch in range(training_epochs): avg_cost = 0. total_batch = int(mnist.train.num_examples/batch_size) for i in range(total_batch): batch_xs, batch_ys = mnist.train.next_batch(batch_size) # 逐个batch的去取数据 sess.run(optm, feed_dict={x: batch_xs, y: batch_ys, keep_prob:0.5}) avg_cost += sess.run(cost, feed_dict={x: batch_xs, y: batch_ys, keep_prob:1.0})/total_batch if epoch % display_step == 0: train_accuracy = sess.run(accr, feed_dict={x: batch_xs, y: batch_ys, keep_prob: 1.0}) test_accuracy = sess.run(accr, feed_dict={x: mnist.test.images, y: mnist.test.labels, keep_prob:1.0}) print("epoch: %03d/%03d cost: %.9f train accuracy: %.3f test accuracy: %.3f" % (epoch, training_epochs, avg_cost, train_accuracy, test_accuracy)) print("done")
我用的显卡是gtx960,在跑这个卷积神经网络的时候,第一次filter分别设的是64和128,结果报蜜汁错误了,反正就是我显存不足,所以改成了32和64,让特征图少一点。所以,是让我换1080的意思喽
i c:\tf_jenkins\home\workspace\release-win\device\gpu\os\windows\tensorflow\core\common_runtime\gpu\gpu_device.cc:885] found device 0 with properties: name: geforce gtx 960 major: 5 minor: 2 memoryclockrate (ghz) 1.304 pcibusid 0000:01:00.0 total memory: 4.00gib free memory: 3.33gib i c:\tf_jenkins\home\workspace\release-win\device\gpu\os\windows\tensorflow\core\common_runtime\gpu\gpu_device.cc:906] dma: 0 i c:\tf_jenkins\home\workspace\release-win\device\gpu\os\windows\tensorflow\core\common_runtime\gpu\gpu_device.cc:916] 0: y i c:\tf_jenkins\home\workspace\release-win\device\gpu\os\windows\tensorflow\core\common_runtime\gpu\gpu_device.cc:975] creating tensorflow device (/gpu:0) -> (device: 0, name: geforce gtx 960, pci bus id: 0000:01:00.0) w c:\tf_jenkins\home\workspace\release-win\device\gpu\os\windows\tensorflow\core\common_runtime\bfc_allocator.cc:217] ran out of memory trying to allocate 2.59gib. the caller indicates that this is not a failure, but may mean that there could be performance gains if more memory is available. w c:\tf_jenkins\home\workspace\release-win\device\gpu\os\windows\tensorflow\core\common_runtime\bfc_allocator.cc:217] ran out of memory trying to allocate 1.34gib. the caller indicates that this is not a failure, but may mean that there could be performance gains if more memory is available. w c:\tf_jenkins\home\workspace\release-win\device\gpu\os\windows\tensorflow\core\common_runtime\bfc_allocator.cc:217] ran out of memory trying to allocate 2.10gib. the caller indicates that this is not a failure, but may mean that there could be performance gains if more memory is available. w c:\tf_jenkins\home\workspace\release-win\device\gpu\os\windows\tensorflow\core\common_runtime\bfc_allocator.cc:217] ran out of memory trying to allocate 3.90gib. the caller indicates that this is not a failure, but may mean that there could be performance gains if more memory is available. epoch: 000/1000 cost: 0.517761162 train accuracy: 0.970 test accuracy: 0.967 epoch: 001/1000 cost: 0.093012387 train accuracy: 0.960 test accuracy: 0.979 . . . 省略
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