create.grid {surveillance} | R Documentation |
algo.hhh.grid
(An auxiliary function for the deprecated HHH estimation
routine algo.hhh.grid
; use hhh4
instead.)
For a given model and a list of parameters specified as param = c(lower,upper,length)
,
create.grid
creates a grid of initial values for algo.hhh.grid
.
The resulting matrix contains all combinations of the supplied parameters
which each are a sequence of length length
from lower
to
upper
.
Note that the autoregressive parameters λ, φ and the
overdispersion parameter ψ must be positive.
Only one sequence of initial values is considered for the autoregressive,
endemic and overdispersion parameters to create the grid,
e.g. initial values are the same
for each one of the seasonal and trend parameters.
create.grid(disProgObj, control, params = list(epidemic = c(0.1, 0.9, 5), endemic=c(-0.5,0.5,3), negbin = c(0.3, 12, 10)))
disProgObj |
object of class |
control |
specified model |
params |
list of parameters:
|
matrix |
matrix with |
M. Paul
# simulate data set.seed(123) disProgObj <- simHHH(control = list(coefs = list(alpha =-0.5, gamma = 0.4, delta = 0.6)),length=300)$data # consider the model specified in a control object for algo.hhh.grid cntrl1 <- list(lambda=TRUE, neighbours=TRUE, linear=TRUE, nseason=1) cntrl2 <- list(lambda=TRUE, negbin="single") # create a grid of initial values for respective parameters grid1 <- create.grid(disProgObj, cntrl1, params = list(epidemic=c(0.1,0.9,3), endemic=c(-1,1,3))) grid2 <- create.grid(disProgObj, cntrl2, params = list(epidemic=c(0.1,0.9,5), negbin=c(0.3,12,10)))