本文实例讲述了Python使用gluon/mxnet模块实现的mnist手写数字识别功能。分享给大家供大家参考,具体如下:
import gluonbook as gb from mxnet import autograd,nd,init,gluon from mxnet.gluon import loss as gloss,data as gdata,nn,utils as gutils import mxnet as mx net = nn.Sequential() with net.name_scope(): net.add( nn.Conv2D(channels=32, kernel_size=5, activation='relu'), nn.MaxPool2D(pool_size=2, strides=2), nn.Flatten(), nn.Dense(128, activation='sigmoid'), nn.Dense(10, activation='sigmoid') ) lr = 0.5 batch_size=256 ctx = mx.gpu() net.initialize(init=init.Xavier(), ctx=ctx) train_data, test_data = gb.load_data_fashion_mnist(batch_size) trainer = gluon.Trainer(net.collect_params(),'sgd',{'learning_rate' : lr}) loss = gloss.SoftmaxCrossEntropyLoss() num_epochs = 30 def train(train_data, test_data, net, loss, trainer,num_epochs): for epoch in range(num_epochs): total_loss = 0 for x,y in train_data: with autograd.record(): x = x.as_in_context(ctx) y = y.as_in_context(ctx) y_hat=net(x) l = loss(y_hat,y) l.backward() total_loss += l trainer.step(batch_size) mx.nd.waitall() print("Epoch [{}]: Loss {}".format(epoch, total_loss.sum().asnumpy()[0]/(batch_size*len(train_data)))) if __name__ == '__main__': try: ctx = mx.gpu() _ = nd.zeros((1,), ctx=ctx) except: ctx = mx.cpu() ctx gb.train(train_data,test_data,net,loss,trainer,ctx,num_epochs)
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