Welford algorithm for updating variance
How can one update the mean, variance, and median of a long list of numbers, after a new element is added?
Recent Posts
Spectral clustering, step by step
How can one relate a seemingly obivous physics concept to linear algebra, and then to a data science problem.
Pivot a Hive table
There is no built-in pivot function in Hive, but one can still do it with relative ease.
Schema on write v.s. schema on read
A runner’s view on this database concept.
Platt scaling for probability calibration
For classification problems, sometimes we care about the narrative of the predicted scores more than the predicted class. But the predicted scores can not al...