python3 pduration.py - returns duration of pandemic depending on R0
python3 pmutation.py - returns dusation and total number of infected dependong on R0
Parameters may be adjusted in the file pandemic.py
n[0] - some initial essential number of infected people. We consider this number as a beginning of pandemic
n_end - the number of infected people that we consider as the end of the pandemic
n[0], n[1], n[2], ... n[k] ... - the sequence of the number of infected people in time
R0 = n[1] / n[0] - basic reproduction number in the beginning of pandemic. This index is decreasing due to the increase in the number of people with immunity and anti-pandemic measures.
N = 7500000000 - the population, approximate number of all people
sigma - the ratio of vaccinated from all people
iwin - immunity window. The number of iterations while immunity is still active. If T = one month, then iwin = 24 corresponds to 1 year of immunity.
S[i] = S[i-1] + n[i-1] - n[i-iwin-1]
n[i+1] = R0 * n[i] * ((1-sigma) * N - S[i]))/((1-sigma) * N)
This recursive dependencies permit us to find the sequence n[0], n[1], n[2], ... n[k] ...
Script pduration.py calculates duration of pandemic depending on R0