[（一）数据清洗](%EF%BC%88%E4%B8%80%EF%BC%89%E6%95%B0%E6%8D%AE%E6%B8%85%E6%B4%97.md) [（二）数据转换](%EF%BC%88%E4%BA%8C%EF%BC%89%E6%95%B0%E6%8D%AE%E8%BD%AC%E6%8D%A2.md) [（三）数据降维之PCA](%EF%BC%88%E4%B8%89%EF%BC%89%E6%95%B0%E6%8D%AE%E9%99%8D%E7%BB%B4%E4%B9%8BPCA.md)