一、引言 前面介绍了两种二元分类算法——感知器算法、口袋算法,这些算法解决的都是分类的问题,但是现实中更多的是例如预测某一地区的房价、银行该给某个人多少额度的信用卡、今天应该买卖多少股票等等这种最后得到一个具体数值结果的问题,这种类型的问题在机器学习中统一被称为回归问题。 回归分析在统计...
In linear regression problems, the cost function J(θ)J(θ) is always a convex function. So gradient descent will correctly find the only global extrema. Specifically, the above algorithm is called batch gradient descent where each step uses all the training examples. feature scaling and mean ...
linear regression problem linear regression algorithm 优化问题 求梯度 算法 generalization issue 是否学到了东西 上限保证 图形观点 测试 linear regression for binary classification main idea 先用LR,把+-1当做Y,利用closed form得到w的值,然后利用LC的公式sign(wx)得到对应的Y值,是可以的。 explaintation 缩小...
这种求解方法也称作顺序算法 (sequential algorithm)(或在线算 (on-line algorithm)),通过迭代每次只考虑⼀个数据点,模型的参数在每观测到数据点之后进⾏更新(实际上一般不会在每个点计算后都更新一次,这样效率极低且误差函数往往震荡不收敛。一般都是在小批量操作的),在迭代过程中通常梯度下降 (gradient descent...
Streaming linear regression GeneralizedLinearAlgorithm GLA,通用线性算法,作为通用回归算法(regression)和分类算法(classification)的抽象算法,run函数中实现了算法的流程,并最终产生通用线性模型。抽象算法流程主要包括:addIntercept, useFeatureScaling, 调用optimizer计算参数等。其中optimizer是抽象类,具体的线性算法需要指定具...
(机器学习应用篇4)9.2 Linear Regression Algorithm (20-03)。听TED演讲,看国内、国际名校好课,就在网易公开课
斯坦福CS229监督学习的第一课——线性回归。在看之前觉得线性回归这么熟悉而又简单,似乎没有必要细看。真正看的时候感觉里面还是包含了一些ML的基本方法和拓展算法的,于是决定写一写。 Linear Regression Overvi…
In many regression problems, you must test a hypothesis involving more than one variable. This option is enabled by default, meaning the algorithm tests a combination of the parameters where two or more parameters are involved. Select the option, Decrease learning rate, if you want ...
Logistic Regression (aka logit, MaxEnt) classifier. In the multiclass case, the training algorithm uses the one-vs-rest (OvR) scheme if the 'multi_class' option is set to 'ovr', and uses the cross-entropy loss if the 'multi_class' option is set to 'multinomial'. (Currently the 'mult...
In many regression problems, you must test a hypothesis involving more than one variable. This option is enabled by default, meaning the algorithm tests a combination of the parameters where two or more parameters are involved. Select the option, Decrease learning rate, if you want the learning...