Matlab中常见的神经网络训练函数和学习函数

深藏阁楼爱情的钟 2022-05-18 05:21 293阅读 0赞

**一、训练函数**

**1、traingd**

**Name**：Gradient descent backpropagation （梯度下降反向传播算法 ）

**Description：**triangd is a network training function that updates weight and bias values according to gradient descent.

**2、traingda**

**Name：**Gradient descent with adaptive learning rate backpropagation(自适应学习率的t梯度下降反向传播算法)

**Description**：triangd is a network training function that updates weight and bias values according to gradient descent with adaptive learning rate. **it will return a trained net (net) and the trianing record (tr).**

**3、traingdx (newelm函数默认的训练函数)**

**name:**Gradient descent with momentum and adaptive learning rate backpropagation(带动量的梯度下降的自适应学习率的反向传播算法)

**Description：**triangdx is a network training function that updates weight and bias values according to gradient descent momentum and an adaptive learning rate.**it will return a trained net (net) and the trianing record (tr).**

**4、trainlm**

**Name：**Levenberg-Marquardt backpropagation （L-M反向传播算法）

**Description：**triangd is a network training function that updates weight and bias values according toLevenberg-Marquardt optimization. **it will return a trained net (net) and the trianing record (tr).**

注：更多的训练算法请用matlab的help命令查看。

**二、学习函数**

**1、learngd**

**Name：**Gradient descent weight and bias learning function （梯度下降的权值和阈值学习函数）

**Description：**learngd is the gradient descent weight and bias learning function, it will **return the** **weight change dW and a new learning state**.

**2、learngdm**

**Name：**Gradient descent **with momentum** weight and bias learning function （带动量的梯度下降的权值和阈值学习函数）

**Description：**learngd is the gradient descent **with momentum** weight and bias learning function, it will **return the weight change dW and a new learning state**.

注：更多的学习函数用matlab的help命令查看。

**三、训练函数与学习函数的区别**

学习函数的输出是权值和阈值的增量，训练函数的输出是训练好的网络和训练记录，在训练过程中训练函数不断调用学习函数修正权值和阈值，通过检测设定的训练步数或性能函数计算出的误差小于设定误差，来结束训练。    
    或者这么说：训练函数是全局调整权值和阈值，考虑的是整体误差的最小。学习函数是局部调整权值和阈值，考虑的是单个神经元误差的最小[1]。
    
    
    参考链接：【1】 https://zhidao.baidu.com/question/1883990061249711708.html?fr=iks&word=matlab%D6%D0traingdx%BA%CDlearngdm%B5%C4%C7%F8%B1%F0&ie=gbk