Engine Evaluation — engine

Evaluate an expression in the TMB-based C++ simulation and objective function engine. This function is useful for trying out the engine_functions that can be used to define macpan2 models.

Usage

engine_eval(
  .expr,
  ...,
  .matrix_to_return,
  .tmb_cpp = getOption("macpan2_dll"),
  .structure_labels = NullLabels()
)

Arguments

.expr: Expression as a one-sided formula, the right-hand-side of which is treated as the expression to be evaluated.
...: Named objects that can be coerced into numeric matrices.
.matrix_to_return: Optional name of one of the matrices given in ... to be returned. If this argument is missing, the matrix that will be returned is the matrix returned by the expression on the right-hand-side of the formula.
.tmb_cpp: Name of a C++ program defining the engine. Typically you just want to use the default, which is macpan2, unless you are extending the engine yourself.
.structure_labels: Deprecated.

Value

Matrix being produced on the right-hand-side or matrix given in .matrix_to_return if it is provided.

Examples

engine_eval(~ exp(y), y = pi) # ~ 23.14069
#>          [,1]
#> [1,] 23.14069

# It is not currently possible to assign values to a subset of
# a matrix in a natural way (e.g. you cannot do things like x[1] = exp(y)),
# but you can achieve this functionality using the assign function.
engine_eval(~ assign(x, 1, 0, exp(y))
  , x = rep(0, 2)
  , y = pi
  , .matrix_to_return = "x"
)
#>          [,1]
#> [1,]  0.00000
#> [2,] 23.14069