Classification in Spark 2.0: “Input validation failed” and other wondrous tales

Christos - Iraklis Tsatsoulis Data Science, Spark 6 Comments

Spark 2.0 has been released since last July but, despite the numerous improvements and new features, several annoyances still remain and can cause headaches, especially in the Spark machine learning APIs. Today we’ll have a look at some of them, inspired by a recent answer of mine in a Stack Overflow question (the question was about Spark 1.6 but, as …

Augmenting PCA functionality in Spark 1.5

Christos - Iraklis Tsatsoulis Dimensionality Reduction, Spark 7 Comments

Surprisingly enough, although the relatively new Spark ML library (not to be confused with Spark MLlib) includes a method for principal components analysis (PCA), there is no way to extract some very useful information regarding the PCA transformation, namely the resulting eigenvalues (check the Python API documentation); and, without the eigenvalues, one cannot compute the proportion of variance explained (PVE), …