陆勤读书：《Machine Learning With R》
第一步：收集数据 Collecting DATA
第二步：探索和准备数据 Exploring and preparing the DATA
第三步：对数据训练模型 Training a model on the DATA
第四步：评价模型性能 Evaluating model performance
第五步：改进模型性能 Improving model performance
2 A key early componet of any machine project involves managing and understanding the data you have collected.
3 Any learning algorithm is only as good as its input data, and in many cases, input data is complex, messy, and spread across multiple sources and formats.
4 Because of this complexity, the largest portion of effort invested in machine learning projects is spent on the data preparation and exploration process.