How to calculate percentile

Think about it for a short while, anyone can see that there is no definitive way to define what is a percentile. What is surprising is how many different ways we can define it. [more]

Downsampling algorithms

This is from a master thesis that try to downsample a line chart (time series) but retain all visual characteristics. What I know about downsampling is to assume the input is a signal and pass it through a low-pass filter, as we have learned in the undergraduate signal & system... [more]