The main use case for using within rather than update or param or init is when you want to update to a new value that is calculated from the existing value. See the example in details

## Usage

# S3 method for mrgmod
within(data, expr, ...)

## Arguments

data

an object with class mrgmod

expr

expressions evaluated in an environment containing various model object components, including parameters, initial conditions, and others (see details)

...

not used

## Details

Other model object slots that can be updated: start, end, delta, add, rtol, atol, hmax, maxsteps. These are include for convenience, but we expect that most of the time these will get updated through the update method.

mod <- mrgsolve::house()
mod$CL #> [1] 1 mod2$CL