Re: slow and steady weighted moving average

[Guest guest]

> It helped when I averaged each week's weight and compared

> those averages for progress. Really, that may

> have worked better than only weighing

> occasionally. I recorded the daily weight in a

> chart in Word for Windows, then programmed the

> chart to extract the average weight for the 7

> days.

Hi. Great idea! I do something similar, called a weighted moving

average. It came from the Hacker's Diet. It's a technique used by

people trying to get noise out of chaotic systems, like a graph of

stock market performance.

Here's how it works:

• take yesterday's weight.

• take todays weight.

• take 0.1 times (yesterdays weight minus today's weight)

• add that to yesterday's weight.

Yesterday's weight has just become the weighted moving average.

• take tomorrow's weight

• subtract it from the weighted moving average (WMA) and add the

difference times 0.1 to the WMA.

Example:

Sunday, weighed 137

Monday, weighed 136

difference is 1. so add -0.1 to 137 to get 136.9 which is now the WMA.

Take the weight Tuesday. It's 136 again. Rounding up from 136.9,

difference is still 1. Add -0.1 to the WMA to get 136.8.

Wednesday shows 135. Rounded difference between 136.8 and 135 is 2, so

add -0.2 to the WMA to get 136.6.

A bunch of salt gets eaten on Wednesday night, so there's waterweight

gain and Thursday's weight is 139.

Rounded difference between 136.6 and 139 is 2. Add +0.2 to 136.6 to get

136.8.

What you wind up with is a curve that follows the actual curve of your

weight lagging by ten days. I have friends whose weight doesn't

fluxuate much at all. Mine swings wildly - often a five pound swing in

a day. This smooths out the curve. If you put it on an excel

spreadsheet, or download the spreadsheets at Hacker's Diet, you can get

a graph of both together.

For someone like me, who has the wild weight swings, it's sometimes

difficult to see where I really am within the noise - or if I'm

actually gaining weight. With the WMA, if my WMA starts climbing once

I'm within my goal range, I will find out before I would have otherwise

and be able to see it as an indication of what behaviors I need to

change.

I think your weekly average would also do the same. I just do this

every day when I fill out my daily weight. Just thought I'd throw it in

just in case someone can use it.

Hope everyone's doing well,

Cheers,

Lee