root_state Derived Type

Previous iterate point used for secant step calculation.

Width of the bracketing interval at the last forced bisection checkpoint.

Absolute value of half the current interval length, |(c - b)/2|.

Internal absolute error tolerance bound, max(abserr, 0.0).

Half-interval vector representation, (c - b)/2.

Function value evaluated at point a, f(a).

Function value evaluated at point b, f(b).

Function value evaluated at point c, f(c).

Maximum initial absolute function value, used to detect poles or divergence.

Numerator of the proposed secant step update fraction (p/q).

Denominator of the proposed secant step update fraction (p/q).

Internal relative error tolerance bound, max(relerr, epsilon).

Dynamic convergence tolerance threshold for the current iteration step.

Counter of sequential secant steps used to force bisection if convergence stalls.

Total number of function evaluations completed so far.