COVID Odyssey: Winter Warning NZ 4 ~ Delta variant 2021 ~ Case numbers appear exponential Dr Bloomfield

New Zealand COVID-19 (Delta variant) Case numbers are exponential.

From today’s NZ Herald (26 August page A4):

CasesNotExponential

Case numbers can be estimated using the formula

C = 1.16 x SQRT(2)^d

where ^ means ‘to the power of’ and

d is the number of days from 10 August 2021.

We estimate the total number of cases in this outbreak by multiplying the number of cases by a factor f.

The final total depends on when the midpoint (peak) is reached.

We assume (hope) the midpoint may be from Saturday 28 August to Monday 30 August.

NZCasesDelta

Depending on when the midpoint (peak) is reached, we estimate the range for the final total to be

CasesMidpoint

Note:
We will allow in another post for the slowdown in the rate of increase near the midpoint. It may only require changing the factor f = 1.9 to a lower number. e.g. 1.7.

If case numbers reach the peak tomorrow (i.e. midpoint Friday 27 August) then the range would be 800 – 1000 cases with the midpoint of the range estimated to be 900 cases.

How likely do you think it will be that the midpoint will come today or tomorrow?

See:

NZCases2021

Note:

It is unwise to extrapolate too far into the future!

There may be more than one “peak”; the graph may be bimodal as it was last year. See:

COVID Odyssey: Winter Warning NZ 5 ~ Estimating the number of 2021 Cases ~ Where will the midpoint be?

COVID Odyssey: Winter Warning NZ 3 ~ Estimating the number of 2020 Cases ~ Where is the midpoint?

You may like to look at these Graphs (they all show the same results) created from the table above:

NZDeltaChart1

NZDeltaChart2

NZDeltaChart3

The graphs clearly show that the case numbers are exponential.

Let’s hope the midpoint (peak) comes early.

Alan Grace

26 August 2021

Also see:

https://aaamazingphoenix.wordpress.com/?s=winter+warning+nz

https://aaamazingphoenix.wordpress.com/

https://aaamazingphoenix.wordpress.com/?s=windup

COVID Odyssey: Winter Warning NZ 3 ~ Estimating the number of 2020 Cases ~ Where is the midpoint?

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