一.Evaluating a Learning Algorithm 训练后测试时如果发现模型表现很差,可以有很多种方法去更改: 用更多的训练样本: 减少/增加特征数目: 尝试多项式特征: 增大/减小正则化参数\(\lambda\). 那么该怎么去选择采用哪种方式呢? 一般将70%的数据作为训练集,30%的数据作为测试集. 先用训练集最小化\(J_{train}(\Theta)\),得到一组参数值\(\Theta\): 然后计算测试集误差\(J_{test}(\Theta)\): 对于线性回归:…

In Week 6, you will be learning about systematically improving your learning algorithm. The videos for this week will teach you how to tell when a learning algorithm is doing poorly, and describe the 'best practices' for how to 'debug' your learning…

(1) Advice for applying machine learning Deciding what to try next 现在我们已学习了线性回归.逻辑回归.神经网络等机器学习算法,接下来我们要做的是高效地利用这些算法去解决实际问题,尽量不要把时间浪费在没有多大意义的尝试上,Advice for applying machine learning & Machinelearning system design 这两课介绍的就是在设计机器学习系统的时候,我们该怎么做? 假设我们实现了一…

https://jmetzen.github.io/2015-01-29/ml_advice.html Advice for applying Machine Learning This post is based on a tutorial given in a machine learning course at University of Bremen. It summarizes some recommendations on how to get started with machin…

7 Machine Learning System Design Content 7 Machine Learning System Design 7.1 Prioritizing What to Work On 7.2 Error Analysis 7.3 Error Metrics for Skewed Classed 7.3.1 Precision/Recall 7.3.2 Trading off precision and recall: F1 Score 7.4 Data for ma…

Passive RFID Basics - AN680 INTRODUCTION Radio Frequency Identification (RFID) systems use radio frequency to identify, locate and track people, assets and animals. Passive RFID systems are composed of three components – a reader (interrogator), pass…

Problem F Lighting System Design Input: Standard Input Output: Standard Output You are given the task to design a lighting system for a huge conference hall. After doing a lot of calculation & sketching, you have figured out the requirements for an e…

http://blog.csdn.net/pipisorry/article/details/44119187 机器学习Machine Learning - Andrew NG courses学习笔记 Machine Learning System Design机器学习系统设计 Prioritizing What to Work On优先考虑做什么 the first decision we must make is how do we want to represent x, that is…

Butler W. Lampson. Hints for computer system design. ACM Operating Systems Rev. 15, 5 (Oct. 1983), pp 33-48 原文地址:http://research.microsoft.com/en-us/um/people/blampson/33-Hints/WebPage.html 简单就是美,做好一件事情,保证稳定高效的基本功能,找好立足点,时刻准备丢弃一个不要的原型,好的一定要复用,分而治之.…

Problem UVA11400-Lighting System Design Accept: 654  Submit: 4654Time Limit: 3000 mSec Problem Description You are given the task to design a lighting system for a huge conference hall. After doing a lot of calculation and sketching, you have figured…