Difference between bfgs.rs and bfgs of optimtool.unconstrain.newton_quasi

[linjing-lab]

In compiled languages, using the method of state to prompt whether to initialize the parameter vector is a consideration for developers not to treat it as a dynamic tuning method, but to use it to adapt to compilation logic for embedded code?

argmin/crates/argmin/src/solver/quasinewton/bfgs.rs

Lines 157 to 161 in a9e3eb7

	let param = state.take_param().ok_or_else(argmin_error_closure!(
	NotInitialized,
	concat!(
	"`BFGS` requires an initial parameter vector. ",
	"Please provide an initial guess via `Executor`s `configure` method."

the above code may be same as the underlined code by given initial point:

gradient = np.array(res.subs(reps)).astype(DataType) # optimtool/unconstrain/newton_quasi.py#L64

argmin/crates/argmin/src/solver/quasinewton/bfgs.rs

Lines 200 to 202 in a9e3eb7

	let param = state.take_param().ok_or_else(argmin_error_closure!(
	PotentialBug,
	"`BFGS`: Parameter vector in state not set."

I have never occured such issue about not set in state, did function parameters make all the initial operations but stop the iteration because of not set in state?

argmin/crates/argmin/src/solver/quasinewton/bfgs.rs

Lines 236 to 238 in a9e3eb7

	let xk1 = sub_state.take_param().ok_or_else(argmin_error_closure!(
	PotentialBug,
	"`BFGS`: No parameters returned by line search."

if I understand here, No parameters means bfgs.rs may stop iteration in intensive program because of line search, and when give a complicated function to adapt to an embedded program, a developer need many trials according to the exact problem which to process.

[stefan-k]

These are safety hatches in case a bug is introduced somewhere. Apart from the check in init, these should never lead to an error in normal operation. The one in init is a hint to the user in case they forget to provide a parameter vector.
This will likely become unnecessary when state handling is improved (#478).

Does this answer your question?

[linjing-lab]

OK, that's really a considerable choice on handling future state.