deSolve-internal {deSolve} | R Documentation |
Internal deSolve Functions
Description
Internal deSolve functions, these are not to be called by the user.
Usage
timestep(prev = TRUE)
Arguments
prev |
if |
Details
Function timestep
is intended to return the current or next
timestep of the integration. It works only under specific
circumstances and should not be used by the end user.
Instead of this, please see the example below for a pure R solution.
See Also
diagnostics
for information about the time steps used,
lagvalue
and lagderiv
that can be used for DDEs.
Examples
###################################################
### This example shows how to retrieve information
### about the used time steps.
###################################################
## a function closure ('lexical scoping')
modelClosure <- function(t0) {
t.old <- t.act <- t0
function(t, y, parms) {
t.old <<- t.act
t.act <<- t
cat(t, "\t", t - t.old, "\n")
with (as.list(c(y, parms)), {
dP <- a * P - b * P * K
dK <- b * P * K - c * K
list(c(dP, dK))
})
}
}
model <- modelClosure(0) # initialization
parms <- c(a = 0.1, b = 0.1, c = 0.1)
y <- c(P = 1, K = 2)
out <- ode(y = y, func = model, times = c(0, 2),
parms = parms, method = "lsoda")
ls() # prove that t.old and t.new are local within 'model'
[Package deSolve version 1.40 Index]