Weight Tracking – Part 2
So, in writing the previous post on my Weight Tracking spreadsheet, I came upon a bit of a conundrum. I wanted to export my graph as an image, but I could not figure out how to do that in Numbers. I am sure that there is a way to do so, but it was not immediately obvious, even with a brief Google search. So, being a good engineer, I decided to roll my own weight tracking script.
Writing my own script has several advantages. First, writing my own script gave me a simple project to begin learning Ruby, something I have been wanting to do. Second, it allows me to extend the script with functionality that might be clumsy in a spreadsheet. Right now, I am just keeping track of the same information that I did in the spreadsheet, dates and weights, only I track it in a simple text file. The script calculates the sliding average for me. If needed, I can easily munge the data in other ways or pull together a secondary text file with other information like my workout routine. I know that I could do the same thing in a spreadsheet, but I like the flexibility that a full programming language gives me over the comparative restraint that I feel when I am hacking together formulas in a spreadsheet. Additionally, my data is kept in a simple text file instead of being tied to a Numbers spreadsheet.
Finally, and most importantly, I was easily able to pull in a library that allowed me to plot my weight and the sliding average of my weight over time and export it as an image file.
There are two obvious improvements that I will likely implement. First, I am calculating the sliding window average of my weight as an integer. That is what causes the strange steps on the graph. I will probably change to calculating the average as a real number, just to make the graph a little smoother. Second, I think that I want to have more points on the X-axis of the graph. Looking at it, I think that the first of each month should be marked on the graph, possibly with lines of demarcation running in the Y-direction at each monthly border. I will have to play around with it and see what all I can do with the graphing library. That is the great thing about being a programmer; if the software you are using does not do what you want it to do, you can either fix it or write your own version.