# COVID Odyssey: Winter Windup ~ 2020 simulations revisited

We revisit the simulations undertaken in early 2020 to estimate the number of people one person with COVID-19 may infect on average over an n-day infectious period.

We developed a formula calculating the numbers Ro and Re (with and without isolation respectively) given a daily rate (r) of increase in cases. We also produced a summary table showing values produced by the formula.

COVID Odyssey: Winter Windup 2 ~ In early 2020 can one person infect 4 or 6 others on average? – COVID Odyssey by Alan Grace: My vir[tu]al COVID-19 journey (wordpress.com)

The simulations each generated 40 sample spreads of COVID-19 with the means for each and the overall means and other stats for the samples.

We found that a daily rate r = 1.4 worked well in New Zealand. We used this in the simulations and also r = SQRT(2) [~1.4142].

Some simulations using n = 10 resulted in values close those calculated by the formula (see the table).

We assume infectivity decreases daily by a factor of 1/r.

The results for sample runs are shown below for the above values for r (only the first 30 values are shown; mean (mu) on the top line is the value calculated by the formula):

More complete results are in the PDFs below:

CSAWsimV3

CSAWsimSQRT2V3B

Below is the formula again and the table:

Search Results for “windup” – COVID Odyssey by Alan Grace: My vir[tu]al COVID-19 journey (wordpress.com)

Shared Posts (Pingbacks) – Share Your Best Posts (wordpress.com)