Exemplo n.º 1
0
def train(train_data,
          net,
          loss,
          ctx,
          global_step,
          epoch_step,
          num_epochs,
          best_F1=0):
    print("Start training on ", ctx)

    if isinstance(ctx, mx.Context):
        ctx = [ctx]

    for epoch in range(num_epochs):
        if epoch == 0:
            learning_rate = 0.001
            print('learning_rate=', learning_rate)
            last_loss = None
            now_loss = None
            trainer = gluon.Trainer(net.collect_params(), 'adam', {
                'learning_rate': learning_rate,
                'wd': 1e-3
            })
        else:
            different = now_loss - last_loss
            if different > 0:
                learning_rate = learning_rate * 0.3
                trainer = gluon.Trainer(net.collect_params(), 'sgd', {
                    'learning_rate': learning_rate,
                    'wd': 1e-3
                })
            print('learning_rate=', learning_rate)
        train_loss, n, = 0.0, 0.0

        start = time()
        for i, batch in enumerate(train_data):
            data, label, batch_size = get_batch(batch, ctx)
            losses = []
            with autograd.record():
                outputs = [net(X) for X in data]
                losses = [loss(yhat, y) for yhat, y in zip(outputs, label)]

            for l in losses:
                l.backward()
            sw.add_scalar(tag='cross_entropy',
                          value=l.mean().asscalar(),
                          global_step=global_step)
            global_step += 1

            train_loss += sum([l.sum().asscalar() for l in losses])
            n += batch_size

            trainer.step(batch_size)

        acc_list, tpr_list, tnr_list, ppv_list, ACC, TPR, TNR, PPV, F1 = tool.evaluate(
            img_path,
            label_path,
            net,
            crop_size=256,
            stride=128,
            ctx=ctx[0],
            threshold=0.5)

        sw.add_scalar(tag='test_acc', value=ACC, global_step=epoch_step)
        sw.add_scalar(tag='test_TPR', value=TPR, global_step=epoch_step)
        sw.add_scalar(tag='test_TNR', value=TNR, global_step=epoch_step)
        sw.add_scalar(tag='test_PPV', value=PPV, global_step=epoch_step)
        sw.add_scalar(tag='F1', value=F1, global_step=epoch_step)
        epoch_step += 1
        print('EPOCH', epoch)

        if F1 > best_F1:
            net.save_parameters('HEI_fold_4.params')
            best_F1 = F1

        print('train_loss=', train_loss / n)
        if epoch == 0:
            last_loss = train_loss / n
            now_loss = train_loss / n
        else:
            last_loss = now_loss
            now_loss = train_loss / n

        print('time:', time() - start)
    sw.close()
Exemplo n.º 2
0
def train(train_data,
          net,
          loss,
          ctx,
          global_step,
          epoch_step,
          num_epochs,
          best_F1=0):
    print("Start training on ", ctx)

    if isinstance(ctx, mx.Context):
        ctx = [ctx]

    for epoch in range(num_epochs):
        if epoch == 0:
            learning_rate = 0.001
            print('learning_rate=', learning_rate)
            last_loss = None
            now_loss = None
            trainer = gluon.Trainer(net.collect_params(), 'adam', {
                'learning_rate': learning_rate,
                'wd': 1e-3
            })
        else:
            different = now_loss - last_loss
            if different > 0:
                learning_rate = learning_rate * 0.3
                trainer = gluon.Trainer(net.collect_params(), 'sgd', {
                    'learning_rate': learning_rate,
                    'wd': 1e-3
                })
            print('learning_rate=', learning_rate)
        train_loss, n, = 0.0, 0.0

        start = time()
        for i, batch in enumerate(train_data):
            data, label, batch_size = get_batch(batch, ctx)
            losses = []
            with autograd.record():
                outputs = [net(X) for X in data]
                losses = [loss(yhat, y) for yhat, y in zip(outputs, label)]

            for l in losses:
                l.backward()
            sw.add_scalar(tag='cross_entropy',
                          value=l.mean().asscalar(),
                          global_step=global_step)
            global_step += 1

            train_loss += sum([l.sum().asscalar() for l in losses])
            n += batch_size

            trainer.step(batch_size)

        acc_list, tpr_list, tnr_list, ppv_list, ACC, TPR, TNR, PPV, F1 = tool.evaluate(
            img_path,
            label_path,
            net,
            crop_size=256,
            stride=128,
            ctx=ctx[0],
            threshold=0.5)
        """
        TP,TN,FP,FN=0,0,0,0
        for data,label in test_data:
            data=data.as_in_context(ctx[0])
            label=label.as_in_context(ctx[0])
            pred=net(data)
            nd.waitall()
            pred=nd.sigmoid(pred)
            pred=(pred>0.5).reshape(-1,256,256)
            
            TPt=nd.sum(pred*label).asscalar()
            FPt=nd.sum(pred-(pred*label)).asscalar()
            FNt=nd.sum(label-(pred*label)).asscalar()
            TNt=nd.sum((1-pred)*(1-label)).asscalar()
            
            TP=TP+TPt
            FP=FP+FPt
            FN=FN+FNt
            TN=TN+TNt

        ACC=(TP+TN)/(TP+TN+FP+FN+1e-15)
        TPR=TP/ (TP+ FN+1e-15)     
        TNR= TN/(FP+TN+1e-15)
        PPV=TP/(TP+FP+1e-15)
        F1=2*PPV*TPR/(PPV+TPR+1e-15)
        print("acc=",ACC)
        print('TPR=',TPR)
        print('TNR=',TNR)
        print('PPV=',PPV)
        print('F1=',F1)
        """
        sw.add_scalar(tag='test_acc', value=ACC, global_step=epoch_step)
        sw.add_scalar(tag='test_TPR', value=TPR, global_step=epoch_step)
        sw.add_scalar(tag='test_TNR', value=TNR, global_step=epoch_step)
        sw.add_scalar(tag='test_PPV', value=PPV, global_step=epoch_step)
        sw.add_scalar(tag='F1', value=F1, global_step=epoch_step)
        epoch_step += 1
        print('EPOCH', epoch)

        if F1 > best_F1:
            net.save_parameters('HEI_fold_1.params')
            best_F1 = F1

        print('train_loss=', train_loss / n)
        if epoch == 0:
            last_loss = train_loss / n
            now_loss = train_loss / n
        else:
            last_loss = now_loss
            now_loss = train_loss / n

        print('time:', time() - start)
    sw.close()