Accessing rxode2 options via getOption slows down solving. This allows the options to be synced with variables.
rxSyncOptions(setDefaults = c("none", "permissive", "strict"))
This will setup rxode2's default solving options with the following options:
"none"
leave the options alone
"permissive"
This is a permissive option set similar to R language specifications.
"strict"
This is a strict option set similar to the original
rxode2(). It requires semicolons at the end of lines and equals for
assignment
nothing; called for side effects