Wish: detect trend

[migueldeicaza]

It is not clear how given the data I can detect a trend, and what the range of time should be for detecting the trend (couple of weeks, a month?)

[roostr]

I think a good first-pass would be:

• Perform all calculations on 7-day SMA data
• Display growth over last 7 days by comparing today's 7-day SMA to 7-days-ago's 7-day SMA
  • Example: "Rate of new cases increased by 15% in last 7 days"

Possibilities for expansion that would be useful to me, at least:

• Configurable: compare over last 14 days, last 21 days, last 28 days
• Rank this rate in terms of all other historical weeks: "This week's rate increase was in the 15th percentile of highest historical weekly increases"
• Draw the rate line as an overlay on the chart

[roostr]

Played with this a bit tonight, found my proposed experiment to be fairly unintuitive. “9% rate increase” doesn’t really register as meaningful information to me.

Going to experiment with translating it into the number of weeks until new cases double: “Doubling every 8 weeks.” and if it’s decreasing, “Halving every 8 weeks.” I sense that’s what would be meaningful to me in a widget.