bracketing methods with CommonSolve interface

[longemen3000]

the CommonSolve interface mentions:

The problem-algorithm-solve interface is a pattern popularized in Julia by the DifferentialEquations.jl suite of packages. This can be used as an alternative to find_zero. Unlike find_zero, solve will return NaN on non-convergence.

But, for bracketing methods, the function Roots.assert_bracket throws:

Roots.jl/src/Bracketing/bracketing.jl

Line 52 in 18354b0

assert_bracket(fx0, fx1) = isbracket(fx0, fx1) || throw(ArgumentError(bracketing_error))

The error path for assert_bracket. also gets activated when one of the values is NaN, instead of returning NaN.

[jverzani]

Hmm, I think of the two cases as different: one is a misspecified problem, the other an algorithm which fails to converge. Maybe I need to clarify that documentation? (Or are you really expecting/wanting NaN for when a bracket isn't properly specified?)

[longemen3000]

In my opinion, The convergence failure should return NaN, the misspecified problem should error.