Gas vs. Electric Car Operating Prices in Honolulu

 Posted on September 11, 2016  |  Michael Ching

Our family has an electric car (Nissan Leaf) and a hybrid (Toyota Prius), and we often have to choose which one we will take out on the weekend. I wondered which one was cheaper to operate and which one was better for the environment. Wallet Impact The Leaf travels about 4.8 miles per kilowatt hour (kwh), and the Prius gets about 55 miles per gallon (mpg). Our electricity costs about $0. [Read More]
cars 

How Late Can My Patient Be

 Posted on August 14, 2016  |  Mike Ching

When a patient doesn’t come to their developmental behavioral pediatrics appointment, it’s bad for my employer, but it’s an unexpected boon for me. Most of my patients seem to come early and only a few arrive later than 5-10 minutes past their appointment time. I wanted to know when I could start to give up on them and start doing something else. When would it be likely that a patient will no-show? [Read More]
health 

Work for Dinosaur Speed Geocache

 Posted on August 5, 2016  |  Mike Ching

This is the work for the geocache we did today. The geocache description instructed us to measure the stride length and footprint length of some dinosaur tracks at the Dinosaur Ridge hike outside of Denver, Colorado. The kids and I looked at both the thinner Ornithomimus tracks and the thicker Iguanodontid tracks. Here’s the work, done in R: First, set up a table of the data. The units for stride length and footprint length are meters. [Read More]

Predicting Flashcard Deck Size Using Linear Regression

 Posted on July 22, 2016  |  Michael Ching

I’m studying for my pediatric recertification board exam right now, and to help me remember things, I’m making flashcards as I read an exam study book. Lately, I’ve been wondering how many flashcards I will have by the time I reach the end of the book. I average about 15 pages a day and about 45 flashcards a day, or 3 flashcards per day. The book itself is 849 pages long, with the real content starting on page 43. [Read More]
prediction 

Reverse-In Parking in Hawaii and California

 Posted on July 14, 2016  |  Mike Ching

Introduction One of my mainland-born friends is annoyed that Hawaii drivers like to reverse their cars into parking stalls much more than the mainland. My wife, who is also from the mainland, agreed with him enthusiastically. Whether this is appropriate parking behavior or not, I had never noticed it before, so I figured it was something I could test with some observations. I had a trip coming up to the mainland, and I was able to collect some data to test whether the Hawaii drivers were really so different than their California counterparts. [Read More]
parking 

Sorting photo directories with R and exiftool

 Posted on June 13, 2016  |  Mike Ching

We were fans of Google’s Picasa photo organization software, but when it was discontinued, I decided that I would like to transfer all my digital photos onto an external drive and then into Adobe Lightroom. To do so, however, my “research” told me that it would be best to group them into catalogs based on year, mainly because I have on the order of 10^5 photos. I had my pictures organized into about 300-400 directories by event. [Read More]

Rolling 3 Doubles in Monopoly

 Posted on May 30, 2016  |  Mike Ching

Tonight my two kids and I were playing Monopoly. It’s a terrible, brutal game that usually ends in bad feelings, but for some reason they always want to play it. One of the rules of the game is that if you roll a double (e.g., two 2s), you get another turn. However, if you roll doubles three times in a row, you are sent to jail. I wondered what was the probability of rolling 3 doubles in a row. [Read More]
simulation 

Up and running!

 Posted on May 29, 2016  |  Mike Ching

This is the start of a new blog for me. I mostly completed the Data Science specialization on Coursera and I use some of these skills in work, but still I am just an amateur at this. I hope to use this site as a sort of notebook to document some of my thoughts and keep my already waning programming skills up. Without peer review, I can’t vouch for the accuracy of anything I say here, so please don’t take anything I write here too seriously! [Read More]