Nothing
N_age <- 5
## mean no. of days in each age compartment (0 - 1 yr, 1 - 5 yr, 5 -
## 15 yr, 15 - 30yr, 30 +)
age_width[1] <- 365 * 1
age_width[2] <- 365 * 4
age_width[3] <- 365 * 10
age_width[4] <- 365 * 15
age_width[5] <- 365 * 20
age_rate[1:(N_age - 1)] <- 1 / age_width[i]
age_rate[N_age] <- 0
den[1] <- 1 / (1 + age_rate[1] / b)
## to work out the % of the population in each age group
den[2:N_age] <- age_rate[i - 1] * den[i - 1] / (age_rate[i] + b)
initial(S[1:N_age]) <- den[i] * (N - I0)
initial(E[1:N_age]) <- 0
initial(I[1:N_age]) <- den[i] * I0
initial(R[1:N_age]) <- 0
I0 <- user(1)
Births <- b * N
b <- 1 / (365 * 50)
N <- 1e7
beta <- 1
sigma <- 1 / 30
delta <- 1 / 60
lat_hum <- 14
I_tot <- sum(I)
surv <- exp(-b * lat_hum)
new_inf[] <- beta * S[i] * I_tot / N
lag_inf[] <- delay(new_inf[i] * surv, lat_hum)
deriv(S[1]) <- - new_inf[i] + delta * R[i] - b * S[i] +
(Births - age_rate[i] * S[i])
deriv(S[2:N_age]) <- - new_inf[i] + delta * R[i] - b * S[i] +
(age_rate[i - 1] * S[i - 1] - age_rate[i] * S[i])
deriv(E[1]) <- new_inf[i] - lag_inf[i] - b * E[i] + (- age_rate[i] * E[i])
deriv(E[2:N_age]) <- new_inf[i] - lag_inf[i] - b * E[i] +
(age_rate[i - 1] * E[i - 1] - age_rate[i] * E[i])
deriv(I[1]) <- lag_inf[i] - (b + sigma) * I[i] +
(- age_rate[i] * I[i])
deriv(I[2:N_age]) <- lag_inf[i] - (b + sigma) * I[i] +
(age_rate[i - 1] * I[i - 1] - age_rate[i] * I[i])
deriv(R[1]) <- sigma * I[i] - b * R[i] - delta * R[i] +
(- age_rate[i] * R[i])
deriv(R[2:N_age]) <- sigma * I[i] - b * R[i] - delta * R[i] +
(age_rate[i - 1] * R[i - 1] - age_rate[i] * R[i])
dim(den) <- N_age
dim(age_width) <- N_age
dim(age_rate) <- N_age
dim(S) <- N_age
dim(E) <- N_age
dim(I) <- N_age
dim(R) <- N_age
dim(new_inf) <- N_age
dim(lag_inf) <- N_age
Any scripts or data that you put into this service are public.
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.