Create a new variable in the simulation_history
by taking sums and products of existing variables (and their
complements and inverses). These new variables can be compared
with observed data streams.
add_sim_report_expr(model, expr_nm, formula)flexmodel object
Name of the new variable
formula describing the expression. See
avail_for_expr for
a function that will return the names of all variables that are available
for use in these formulas.
updated flexmodel object