Thursday, July 8, 2010

Geek Time

I thought it might me interesting to look at my weight loss in a mathtastic way.  I spent quite a bit of time futzing with Microsoft's more nerdy functions in Word and Excel to figure out the most accurate and understandable plot for my weight loss.  Plotting the data into a scatter plot was pretty easy.  Figuring out the right trend line to extrapolate the data into the future was the tricky part.  I tried linear, which was a bit clumsy.  I tried logarithmic, which I am too far removed from Calculus to completely understand.  I know what the numbers say, and I know the trend line looked right, but I couldn't say why and that is no use as a tool.  I finally decided on a good old exponential trend line.  I had to put in data to get the graph out to my goal weight, right now set at 220.1, so I entered a rough average of 2.5 pounds per week, which gets me to the goal weight on week 70 of this journey.  The trend line I got works great.  What is more it looks like I am consistently pushing that trend line down, which gets me to my goal more quickly.  For my math inclined friends here is my weight loss extrapolated and presented as a function: y = 426.35e^-0.009x.  This chart, other than being kinda cool, allows me to see how my week by week weight loss fits into the grand scheme of things.  It should be a great way to keep me on track.  Here is the chart itself: