Author Archives: mathscinotes

An Example of Cleaning Untidy Data with Tidyr

I recently decided to take some classes in data analysis at Datacamp, an online training site. My first classes were in dplyr and tidyr – two excellent R-based tools for manipulating files that not amenable to analysis because of inconsistencies and structure: tidyr provides many tools for cleaning up messy data, dplyr provides many tools for restructuring data. After completing the two classes, I decided that I needed to firm up my knowledge of these tools by applying them to a concrete example. Continue reading

 
Posted in Excel, History Through Spreadsheets | Leave a comment

Quick Look at Large US Dams

I was on the phone this morning with a coworker who lives in California, about 150 miles south of the Oroville dam (Figure 1). This dam has recently been in the news because of concerns that spillway erosion could cause a dam failure. At one point, nearly 200K people were evacuated from the potential flood zone. Continue reading

 
Posted in Excel, History of Science and Technology | 3 Comments

Daily Tree Consumption for Toilet Paper

I was reading an article on National Geographic when I spotted an interesting factoid about the impact of Toilet Paper (TP) world-wide tree consumption.

Toilet paper wipes out 27,000 trees a day.

Like many factoids, I doubt there is a way to actually measure this number – it can only be estimated. Thus, it is a prime candidate for a Fermi solution. Continue reading

 
Posted in General Mathematics, General Science | 4 Comments

Fact Checking: US Murder Rate Over Time

I recently saw a politician claim that the US murder rate is the "highest it's been in 47 years." This is an easy fact to check and provided me another Power Query example to provide for my staff. Continue reading

 
Posted in Excel, Fact Checking | 2 Comments

Fact Checking: Comparison of Military Budgets

I heard a news commentator say that the US defense budget is larger than the combined defense budgets for the next ten largest spenders. I thought that this would be easy to check and would provide my staff a beginner's example to use for their Excel self-training. Continue reading

 
Posted in Civics Through Spreadsheets, Fact Checking | 2 Comments

History Through Spreadsheets: Executive Orders

During my recent seminar on Excel's Power Query feature, I showed my team how to grab data executive order data from the web and generate a simple plot (Figure 1). After generating the plot, I asked the audience what we could learn from this graph. I was expecting to hear that the early 1900s – the time between Teddy Roosevelt and Franklin Roosevelt – was a time of massive use of executive orders. Continue reading

 
Posted in Civics Through Spreadsheets, Excel, History Through Spreadsheets | 3 Comments

History Through Spreadsheets: Supreme Court Confirmations

I recently gave a seminar to my staff on using Excel with Power Query. As part of the seminar, I presented a number of web scraping examples that were well received, and I decided that some of you may appreciate them also. Continue reading

 
Posted in History Through Spreadsheets | Leave a comment

US Manufacturing Employment Versus Time

The only television news program that I watch is the PBS Newshour. I particularly like the discussions between Mark Shields, a reasonable liberal, and David Brooks, a reasonable conservative. On inauguration day (20-Jan-2017), they had an interesting discussion about the challenges the US faces and what can be done about them. Continue reading

 
Posted in History Through Spreadsheets, Statistics | 4 Comments

Slide Rules of the Rocket Pioneers

I was watching a interview with Valerie Neal, Curator and Chair National Air and Space Museum, on CSPAN. The interview was focused on the history of rocket development in both the US and Soviet Union. Valerie was asked what was her favorite artifact at the National Air and Space Museum. She responded that she liked artifacts that were the personal items of the pioneers. In the case of space travel, she said that the slide rules of rocket pioneers Wernher von Braun and Sergei Korolev were her favorite artifacts. Both men used the same type of slide rule. As I looked closely at the slide rules (Figures 2 and 3), I realized they were the same brand – Nestler – as used by some engineers I knew as a boy. My slide rule was a Pickett, similar to that shown in Figure 1. Continue reading

 
Posted in History of Science and Technology | 2 Comments

Futurama Quote on Largest Buggalo Ranch on Mars

I am a big fan of Futurama – its going off the air was as disappointing for me as discovering Firefly a few years ago and having only 14 episodes to watch. I love the fact Futurama often includes small bits of real math and science in its scripts. My all time favorite piece of math includes a blackboard showing an actual proof using group theory by Sweet Clyde in the episode "The Prisoner of Brenda." Continue reading

 
Posted in Humor | 2 Comments