The Function used to quantify this loss during the training phase in the form of a single real number is known as “Loss Function”. These are used in those supervised learning algorithms that use optimization techniques. Notable examples of such algorithms are regression,logistic regression, etc....
吴恩达(详解机器学习)【中英字幕】-08-单变量线性回归成本函数Cost function Intution 19播放 吴恩达(详解机器学习)【中英字幕】-07-成本函数Cost function 49播放 吴恩达(详解机器学习)【中英字幕】-06-线性回归Linear regression Part2 8播放 吴恩达(详解机器学习)【中英字幕】-05-线性回顾归Linear regression Part1...
2.平方损失函数(quadratic loss function) L ( Y , f ( X ) ) = ( Y − f ( x ) ) 2 L(Y,f(X)) = (Y – f(x))^2 L(Y,f(X))=(Y−f(x))2 3.绝对值损失函数(absolute loss function) L ( Y , f ( x ) ) = ∣ Y − f ( X ) ∣ L(Y,f(x)) = |Y – f...
We cannot use the same cost function that we use for linear regression because the Logistic Function will cause the output to be wavy, causing many local optima. In other words, it will not be a convex function. non-convex: convex: Instead, our cost function for logistic regression looks l...
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神经网络基础篇:详解logistic 损失函数(Explanation of logistic regression cost function) 详解logistic 损失函数 在本篇博客中,将给出一个简洁的证明来说明逻辑回归的损失函数为什么是这种形式。 回想一下,在逻辑回归中,需要预测的结果^yy^,可以表示为^y=σ(wTx+b)y^=σ(wTx+b),σσ是熟悉的SS型函数σ(z)...
We carry out detailed study of the phase space of a small neural network in a paradigmatic machine learning regression problem. In spite of its simplicity, the system phase space turns to be extremely complex with a plenty of local minima of the cost function. These minima differ in depth ...
线性回归(Linear Regression),数理统计中回归分析,用来确定两种或两种以上变量间相互依赖的定量关系的一种统计分析方法。 线性回归模型: ε表示误差项,也叫随机干扰项,即真实值和预测值之间的差异。ε服从均值为0的正态分布,其中只有一个自变量的情况称为一元线性回归,多个自变量的情况叫多元线性回归。
代价函数(有的地方也叫损失函数,Loss Function)在机器学习中的每一种算法中都很重要,因为训练模型的过程就是优化代价函数的过程,代价函数对每个参数的偏导数就是梯度下降中提到的梯度,防止过拟合时添加的正则化项也是加在代价函数后面的。 在学习相关算法的过程中,对代价函数的理解也在不断的加深,在此做一个小结。
1% Compute Costforlinear regression2%cost Function函数实现___利用矩阵操作进行!!3function J =computeCost(X, y, theta)45%Initialize some useful values6m = length(y); %number of training examples7J =0;89%Instructions: Compute the cost of a particular choice of theta10% You shouldsetJ to the...