tests/testthat/test-human_sis.R

In exDE: Extensible Differential Equations for Mosquito-Borne Pathogen Modeling

library(deSolve)

test_that("human SIS model remains at equilibrium", {
  nStrata <- 3
  H <- c(100, 500, 250)
  X <- c(20, 120, 80)
  b <- 0.55
  c <- 0.15
  r <- 1/200
  Psi <- matrix(data = 1,nrow = 1, ncol = nStrata)

  EIR <- diag(1/b, nStrata) %*% ((r*X)/(H-X))

  params <- list(
    nStrata = nStrata
  )
  params <- list2env(params)

  make_parameters_X_SIS(pars = params, b = b, c = c, r = r, Psi = Psi, X0 = X, H = H)
  make_indices(params)

  y0 <- rep(0, 3)
  y0[params$X_ix] <- X

  out <- deSolve::ode(y = y0, times = c(0, 365), func = function(t, y, pars, EIR) {
    list(dXdt(t, y, pars, EIR))
  }, parms = params, method = 'lsoda', EIR = as.vector(EIR))

  expect_true(all(approx_equal(as.vector(out[2L, params$X_ix+1]), X)))
})