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]

O-R-I-D focused conversation

Recently I found the ORID conversation method a hot topic in Taiwan. I can even see Audrey Tang (of Perl 6) have a video explaining how she use it in her job in the government. Below are some notes and examples, and all the web resources from which I learned... [more]

Simplifying surds

Recently I am investigating some geometric construction (i.e., compass and ruler constructions) and encounter into the issue of finding sine for some angles. I remember most whole number degree angles could be expressed in surd forms, only it is less pretty than the standard angles of 30°, 45°, 60°. Mostly... [more]