Thursday, April 16, 2020

Bending the Curve


 

Both Doctors Birx and Fauci keep pointing to”bending the curve” and “logarithmic growth” as key elements in determining when we will emerge from the COVID-19 woods. What do these terms mean? Dear reader, in this blog post, I will try to explain.

I have previously pointed you to the Latest Data link to show you the numbers describing what is happened with the coronavirus case and mortality statistics. The first two charts show how the numbers are progressing worldwide. At the top of each chart you have the option between linear and logarithmic forms of these numbers. Why logarithmic? 

Because there is a convenient mathematical trick that allows you to quickly assess the growth rate of the underlying raw data. Neato!

To see this trick in action chick on the logarithmic option on say the worldwide Coronavirus Cases chart. Now look at the slope of this logarithm curve at various points. To convert this slope estimate into a growth rate look at the above table ... converting the rightmost column to degrees by multiplying by 100. Then read the growth rate from th left column. As one can see, when the slope of the curve on the logarithmic trend line flattens, the “growth rate” of the raw numbers is zero ... meaning not that the numbers are going down, just the change in these numbers is unchanging.

Click on the top table entry  “US” link to drill down into the numbers just for America and perform this same mathematical trick.

One can also see that the actual numbers will not decrease until the slope of the logarithmic transform is also negative. So, dear readers, if you want to track things like Dr. Birx, take a daily excursion into the above link and click on the logarithmic options on these charts. (At the moment, the logarithmic cases chart DOES show a flattening of the curve ... good news!) A flattening of the deaths chart will be delayed by a week or two.

2 comments:

Anonymous said...

Dennis, do you have any idea what George is talking about??? Please explain to us dump f's. Thanks.

DEN said...

No, Bill, I never went beyond Geometry (and even there I barely passed.) My eyes glazed over as soon as I saw the word "logarithmic." The amusing thing is to imagine what it is like for Fauci and Birx to explain this to the stable genius.

George is just using this math sophistry to try and distract us from the Fox Agenda: let some people die so the rest of us can can get back to work. Cull the herd for the greater good.
They hope the fatalities will mainly be would-be democratic voters.

I'm sure the other two followers of this blog are more mathematically erudite.