Tim Cogan's Blog

One of my hobbies is fishing, and it just so happensthat Texas, where I live, is one of thebest states for fishing.

When I’m not fishing with a lure, I like to use atungsten slip sinker, which is nice for a couple of reasons:

Traditional lead sinkers are potentially bad for the environmentand bad for you. Tungsten has a higher density than lead (19.3g/cm319.3 g/cm^{3}19.3g/cm3 versus 11.3g/cm311.3 g/cm^{3}11.3g/cm3), arguably making it better sinker material.The primary disadvanta...

Earlier this month, my dad sent me a resource for self-hosting a ChatGPT-like AI.

And this led to a conversation that sparked an idea:

Set up a private chat AI, reachable via Signal messaging.

A few Bash & Python scripts later, our system was up and running.

And we’ve been having a lot of fun with it.

I think others will also enjoy this, so I’m sharing a public repository for the Private AI Project.

Reasons to self-host a chat AI:

• Keep your chat history 100% private.

• Message your AI ...

A little over five years ago, my advisor, Dr. Lakshman Tamil, and I began developing an AI for early breast cancer detection.

I don’t think I can adequately cover the last 5+ years in this short post, but I will say that it has been quite an adventure.

It’s been a road with many challenges yet also many successes.

A pivotal milestone was the creation of MedCognetics, bringing together a team passionate about transforming healthcare and women’s health.

And today, I’m pleased to share this tea...

By way of my career, I’ve had the immense pleasure of traveling to many parts of the world. And earlier this month, I had the opportunity to visit India for the first time.

The food I ate and the places I saw were unforgettable. Pictures do no justice, particularly for the Taj Mahal.

Visiting the Taj Mahal is the experience of observing, approaching, and finally stepping into a painting. To explore it means to feel as though you’ve entered into another’s imagination.

However, my favorite part...

I’m happy to announce the release of Data Science for Babies, 2nd edition, and I’d like to thank everyone who has provided feedback, suggestions, and critiques across all of my books.

Here’s a link to a book trailer which was straightforward to create. Since my books are compiled with a Python-based framework, changing the compilation process to produce a video file instead of a book PDF was just a few dozen lines of code.

If you’re interesting in getting a copy of the book, please check out t...

My son, Silas, has started asking a recurring question.

Some mornings around 7am, Silas stumbles into my office, still half asleep, and asks,

“Dad, did you write another cookie book?”

A moment passes as I finish typing out a line of code, and I usually answer something like,

“No, Buddy, not today.”

However, recently I was able to say, “Yup, a draft is ready! Can you read it and make suggestions?” and then see a smile pop onto his face.

A few revisions later, following lots of good feedback...

This post walks through a simple LZSS compression implementation, written in Python.

Background

The LZSS code I’m presenting here is based on thisGitHub project,but I’ve created my own forkwith some improvements and optimizations.

For some background on LZSS, Wikipediahas a pretty good description.

The remainder of this post will walk through an implementation ofcompression followed by decompression.

CompressionOverview

The main function for compression is fairly short:

def compres...

Earlier this year, I published a bookfor teaching data science concepts to young children.While writing this book, I thought of a few other engineering concepts that I would like to include in a subsequent book.

I’ve titled this subsequent book “DevOps for Sponges”, and it teaches software development and operationsconcepts such as version control, automation, testing, deployment, and incremental design.

Why is the book “for Sponges”? Children are likened to sponges because of their ability...

For those of you with kids or young relatives, you know it can be a challenge explaining to kiddos why you have to work and what you do at work all day.

To make my own work a bit more relatable, I recently wrote a book to explain data science in the simplest terms possible with the hope of inspiring and educating the youngest of minds.

With very basic examples, this book covers regression, statistical overfitting & underfitting, classification, data visualization, and time series analysis.

Th...

This post walks through an implementation of theLeGall-Tabatabai wavelet transform.

Introduction

If you haven’t read my previous poston performing the Haar wavelet transform, be sure to check it out to developa good foundation for the content we’ll be exploring in this post.I also found this postto be a helpful reference when reading up on LGT transforms.

The LGT (5/3) wavelet transform we’ll be working with is a bit more complex than theHaar wavelet transform but offers characteristics...