machine learning(9) -- classification:Decision boundary 上图的decision boundary是一条直线,是属于预测函数的一个属性(当参数已经确定),不是数据集的属性. decision boundary是根据预测函数得来的,而不是根据数据集得到的.数据集(trainning data)是用来确定参数(θ0,θ1,θ2....)的 上图的decision boundary不是直线而是一个圆,需要create more features f…

其它的比gradient descent快, 在某些场合得到广泛应用的求cost function的最小值的方法 when have a large machine learning problem,一般会使用这些advanced optimization algorithm而不是gradient descent Conjugate gradient, BFGS,L-BFGS很复杂,可以在不明白详细原理的情况下进行应用(使用software libary). 可以使用Octave和matlab的…

分类预测不能使用linear regression, linear regression算法对于分类预测效果很差,应使用logistic regression算法 Logistic regresstion = a Classification algorithm 一种分类预测算法 Logistic regression model:  Sigmoid function = Logistic function   Logistic function的曲线图(y值处于0与1之间[z->+∞时g(z)…

Multiclass classification例子: 邮箱的邮件的分类: 工作邮件,私人邮件,朋友的邮件,兴趣爱好的邮件 医学诊断: 没有生病,患有流感,患有普通感冒 天气: 晴天,兩,多云等 One-vs-all classfication = one-vs-rest : 每一次将一个class分出来,共构建3个classifiers hθ(i)(x) = P(y=i|x;θ)    (i=1;2;3) train a logistic regression classifier hθ(i…

logistic regression cost function(single example) 图像分布 logistic regression cost function(m examples) Writting cost function in a more convenient form with just one line To fit parameter θ Using gradient descent to minimize cost function 看上去和gradient…

Machine Learning for Developers Most developers these days have heard of machine learning, but when trying to find an 'easy' way into this technique, most people find themselves getting scared off by the abstractness of the concept of Machine Learnin…

About me In my spare time, I love learning new technologies and going to hackathons. Our hackathon project Pantrylogs using Artificial Intelligence was selected as one of the 10 Microsoft Imagine Cup UK finalists. I’m interested in learning more abou…

How do you explain Machine Learning and Data Mining to non Computer Science people?   Pararth Shah, ML Enthusiast Answered Dec 22, 2012 · Featured on VentureBeat · Upvoted by Melissa Dalis, CS & Math major at Duke and Alberto Bietti, PhD student in m…

原文地址:http://www.demnag.com/b/java-machine-learning-tools-libraries-cm570/?ref=dzone This is a list of 25 Java Machine learning tools & libraries. Weka has a collection of machine learning algorithms for data mining tasks. The algorithms can either be…

Problems[show] Classification Clustering Regression Anomaly detection Association rules Reinforcement learning Structured prediction Feature engineering Feature learning Online learning Semi-supervised learning Unsupervised learning Learning to rank…