Category Archives: Excel

I use Python, R, and Excel every day in the course of my work. Because many corporations are focused on the Microsoft Office suite of tools, many businesses require that I use Excel/Power Query so that they can work with the tools I develop after I am done. Fortunately, I really enjoy using Power Query, but I find it irritating that it does not support regular expressions. I must admit that Power Query's standard functions can do a good job of extracting strings, but the process is a bit tedious.  However, I have a large library of regular expressions for extracting email addresses, phone numbers, social security numbers, and the like that would be efficient for me to use. Continue reading →

I recently volunteered to do some pro-bono data analysis and front-end web development for a very nice Kenyan woman who is trying to provide a US distribution channel for some coffee growers in her native Kenya. This post documents my work on tidying her coffee data. Continue reading →

I was recently given a specification for a Digital-to-Analog Converter (DAC) that contains a table of register settings that correspond to the DAC's output voltage. Each row of the table corresponds to one register setting and each column corresponds to a register bit. Thus, each table cell corresponds to a single bit – a 1 or 0. A simplified version of this table is shown in Figure 1 – a simplified version of the much larger table I was working with. Continue reading →

I have been analyzing seemingly random fuse failures in different products. The failing fuse is similar to the unit shown in Figure 1. My analysis has shown that the fuses are failing because of damage they are sustaining during the manufacturing process. In my analysis report, I was asked to list each product that experienced a fuse failure and to list how many days each product was in service before the fuse failure occurred. Continue reading →

While working on a test report for an aircraft manufacturer this week, I needed to convert a large number of number lists to strings of dashed ranges. For example, suppose you are given a list {1, 2, 3, 5, 6, 7, 8, 10}. Converting this list to a dashed set of ranges means generating the string "1-3, 5, 6-8, 10." Figure 1 shows another example with an optional prefix added to each number. Continue reading →