Regularized logistic regression :  plot data(画样本图) ex2data2.txt 0.051267,0.69956,1-0.092742,0.68494,1-0.21371,0.69225,1-0.375,0.50219,1-0.51325,0.46564,1-0.52477,0.2098,1-0.39804,0.034357,1-0.30588,-0.19225,10.016705,-0.40424,10.13191,-0.51389,10.385…

Regularized logistic regression : mapFeature(将feature增多) and costFunctionReg ex2_reg.m文件中的部分内容 %% =========== Part 1: Regularized Logistic Regression ============% In this part, you are given a dataset with data points that are not% linearly separabl…

不同的λ(0,1,10,100)值对regularization的影响\ 预测新的值和计算模型的精度 %% ============= Part 2: Regularization and Accuracies =============% Optional Exercise:% In this part, you will get to try different values of lambda and % see how regularization affects the decisio…

Regularization:Regularized logistic regression without regularization 当features很多时会出现overfitting现象,图上的cost function是没有使用regularization时的costfunction的计算公式 with regularization 当使用了regularization后,使θ1到n不那么大(因为要使J(θ)最小,θ12+θ22.....θn2->0这时θj要趋向于0),这样可以避免…

要解决的问题是,给出了具有2个特征的一堆训练数据集,从该数据的分布可以看出它们并不是非常线性可分的,因此很有必要用更高阶的特征来模拟.例如本程序中个就用到了特征值的6次方来求解. Data To begin, load the files 'ex5Logx.dat' and ex5Logy.dat' into your program. This dataset represents the training set of a logistic regression problem with t…

题目 在本部分的练习中,您将使用正则化的Logistic回归模型来预测一个制造工厂的微芯片是否通过质量保证(QA),在QA过程中,每个芯片都会经过各种测试来保证它可以正常运行.假设你是这个工厂的产品经理,你拥有一些芯片在两个不同测试下的测试结果,从这两个测试,你希望确定这些芯片是被接受还是拒绝,为了帮助你做这个决定,你有一些以前芯片的测试结果数据集,从中你可以建一个Logistic回归模型. 编程实现 在这部分训练中,我们将要通过加入正则项提升逻辑回归算法.简而言之,正则化是成本函数中的一个术语…

针对逻辑回归问题,我们在之前的课程已经学习过两种优化算法:我们首先学习了使用梯度下降法来优化代价函数…

编程作业文件: machine-learning-ex2 1. Logistic Regression (逻辑回归) 有之前学生的数据,建立逻辑回归模型预测,根据两次考试结果预测一个学生是否有资格被大学录取. 载入学生数据,第1,2列分别为两次考试结果,第3列为录取情况. % Load Data % The first two columns contain the exam scores and the third column contains the label. data = load(…

Logistic regression is a method for classifying data into discrete outcomes. For example, we might use logistic regression to classify an email as spam or not spam. In this module, we introduce the notion of classification, the cost function for logi…

%% ============ Part : Compute Cost and Gradient ============ % In this part of the exercise, you will implement the cost and gradient % for logistic regression. You neeed to complete the code in % costFunction.m % Setup the data matrix appropriately…