import tensorflow as tfdef cross_entropy_loss(y_true, y_pred): # 计算交叉熵损失 cross_entropy = tf.nn.softmax_cross_entropy_with_logits(labels=y_true, logits=y_pred) return tf.reduce_mean(cross_entropy)def boundary_loss(y_true, y_pred): # 计算边界损失 boundary_filter = tf.constant([[0, 1, 0], [1, -4, 1], [0, 1, 0]], dtype=tf.float32) y_true_boundary = tf.nn.conv2d(y_true, boundary_filter, strides=[1, 1, 1, 1], padding='SAME') y_pred_boundary = tf.nn.conv2d(y_pred, boundary_filter, strides=[1, 1, 1, 1], padding='SAME') boundary_loss = tf.reduce_mean(tf.square(y_true_boundary - y_pred_boundary)) return boundary_lossdef total_loss(y_true, y_pred): # 总损失函数 = 交叉熵损失 + 边界损失 return cross_entropy_loss(y_true, y_pred) + 0.5 * boundary_loss(y_true, y_pred)# 构建模型model = ...# 编译模型model.compile(optimizer='adam', loss=total_loss, metrics=['accuracy'])
时间: 2024-03-29 21:39:27 浏览: 113
custom-models-layers-loss-functions-with-tensorflow:自定义模型层损失功能与张量流
可以将这部分代码转化为PyTorch,转化后的代码如下:
import torch
import torch.nn as nn
import torch.nn.functional as F
def cross_entropy_loss(y_true, y_pred):
# 计算交叉熵损失
cross_entropy = nn.CrossEntropyLoss()(y_pred, y_true)
return cross_entropy
def boundary_loss(y_true, y_pred):
# 计算边界损失
boundary_filter = torch.tensor([[0, 1, 0], [1, -4, 1], [0, 1, 0]], dtype=torch.float32)
boundary_filter = boundary_filter.view(1, 1, 3, 3)
y_true_boundary = F.conv2d(y_true, boundary_filter, padding=1)
y_pred_boundary = F.conv2d(y_pred, boundary_filter, padding=1)
boundary_loss = F.mse_loss(y_true_boundary, y_pred_boundary)
return boundary_loss
def total_loss(y_true, y_pred):
# 总损失函数 = 交叉熵损失 + 边界损失
return cross_entropy_loss(y_true, y_pred) + 0.5 * boundary_loss(y_true, y_pred)
# 构建模型
class Model(nn.Module):
def __init__(self):
super(Model, self).__init__()
self.conv1 = nn.Conv2d(in_channels=3, out_channels=16, kernel_size=3, stride=1, padding=1)
self.conv2 = nn.Conv2d(in_channels=16, out_channels=32, kernel_size=3, stride=1, padding=1)
self.pool = nn.MaxPool2d(kernel_size=2, stride=2)
self.fc1 = nn.Linear(32*8*8, 128)
self.fc2 = nn.Linear(128, 10)
def forward(self, x):
x = F.relu(self.conv1(x))
x = self.pool(F.relu(self.conv2(x)))
x = x.view(-1, 32*8*8)
x = F.relu(self.fc1(x))
x = self.fc2(x)
return x
model = Model()
# 编译模型
optimizer = torch.optim.Adam(model.parameters(), lr=0.001)
loss_fn = total_loss
metrics = ['accuracy']
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