Normally when folks calculate an asset’s weighted average life they use the formula $$ WAL = {{\sum_n{n \cdot Prin_n}} \over Par_0} $$ where $$ Par_n = \hbox{Par value at time n} \\[7pt] $$ and $$ Prin_n = \hbox{Principal payment at time n} \\[7pt] $$

In a previous blog post I had presented this formula $$ WAL = {\sum{Par_n} \over Par_0} \\ $$ without any context, other than to leave it to the reader to prove.

Advent Calendars

I bought a candy advent calendar for my wife and a whiskey advent calendar for me. I hope to write reviews for both every day, but I’ll give the over under at April for when I actually write it lol =P.

In previous years we got Advent calendars for the animals. Funny thing - dog Advent calendars are almost always treats, cat advent calendars are almost always toys, and horse Advent calendars… okay those don’t exist to my knowledge (or would be very expense). At the end of the day we were left with a bunch of cat toys that that the cats leave everywhere for the Roomba to eat

This year we got the Sugarfina Advent Calendar as well as the 2023 Flaviar Whiskey Advent Calendar . I was content to leave the candy to Barb and the Whiskey to me, but Barb decided she wants to try whiskey, so now I have to share. At least the calendar came with two glasses!

Well it’s the end of the year so it’s that time that I tell you to go check out my media wrap up for the year! Inspired by my friend Jen I started a media log, or at least keeping some kind of track of all the books I read, Jen catalogs all her media and I am not nearly that organized or ambitious. However, I did add a new entry this year for Unconventional Christmas Movies where I ramble on about Christmas horror movies in addition to my annual book writeup (that usually gets procrastinated until the end of the year lol)

You can check out the entirety of my media log here

Die Hard is a Christmas Movie

I said what I said. Read more of my weird assed takes on Christmas movies in my post Unconventional Christmas Movies

Building a Hénon map with javascript

I first found out about the Hénon map as an undergrad and have loved it ever since. Can I simulate it in javascript? Let’s find out!

The Hénon map is a dynamical system that exhibits chaotic behavior. It takes two parameters a and b. Depending on the values the map can exhibit periodic , chaotic or intermittent (switching back and forth between chaotic and stable orbits). It is described by the formula:

$$ \begin{aligned}
x_{n+1} &= 1 - ax_n^2+y_n\\ y_{n+1} &= bx_n \end{aligned}
$$

The Hénon map is basically taking the x-y plane and stretches, folds and squishes it like kneading bread. For some parameters it will tend toward a fixed point or set of points, but for others it exhibits chaotic dynamics - which means that no matter how accurately you describe the current position, it will be impossible to predict where it will be in the future (other than within the bounds of the attractor).

My Random Meditation Video Generator

I’ve been collecting a group of meditation videos on YouTube that I use to manage anxiety. This is mostly a place for me to come, press a button and get a random meditaiton video. So if you’d like a random meditation video to help with anxiety click the button below!