library(ramp.xds)
J = make_residence_matrix(3, c(1,1,2,2))
J [,1] [,2] [,3] [,4]
[1,] 1 1 0 0
[2,] 0 0 1 1
[3,] 0 0 0 0Stratification
Heterogeneity in Human Malaria Epidemiology
Simple models of malaria assume that everyone is alike, but populations can be heterogeneous in various ways:
heterogeneous exposure and transmission
location
housing quality
heterogeneous behaviors
care seeking
drug taking or adherance
age and immunity
heterogeneity created by malaria control
- vaccination
Residency
An important aspect of human population strata for most models is the location of home.
Even if risk is distributed, information about malaria in humans is often aggregated by the location of home. For an ordered list of population strata, the residence vector is a list of patch indices for those strata: \[\left[i, j, k, ..., y, z \right]\] The residence matrix, \(J,\) is a \(N_p \times N_h\) matrix where the \(i,j^{th}\) entry is 1 if the \(i^{th}\) stratum lives in the \(j^{th}\) patch.
For example, if there are four strata, two live in patch 1 and two in patch 2, then the residence vector is: \[\left[1, 1, 2, 2 \right]\] and the residence matrix is:
If \(H = \left[10, 100, 20, 200 \right]\) is a column vector describing the size of the strata, then \(J\cdot H\) is a vector of length \(N_p\) that is the resident population size for all three patches:
J %*% matrix(c(10, 100, 20, 200), 4, 1) [,1]
[1,] 110
[2,] 220
[3,] 0