Difference between revisions of "Alpha conds.m"

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(Update function See also links and function index membership)
(sync with Spinach main f053e432: Parameters/Outputs blocks aligned with head header)
 
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==Parameters==
 
==Parameters==
  
−
        test_type        - condition selector:
+
    test_type        - condition selector:
−
                            0 for monotonic increase test
+
−
                            1 for Armijo sufficient increase test
+
                        0 for monotonic increase test
−
                            2 for strong Wolfe curvature test
+
                        1 for Armijo sufficient increase test
−
                            3 for ascent direction test
+
                        2 for strong Wolfe curvature test
−
        alpha            - trial step length
+
                        3 for ascent direction test
−
        fx_0              - objective value at the initial point
+
−
        fx_1              - objective value at the trial point
+
    alpha            - trial step length
−
        gfx_0            - gradient at the initial point
+
−
        gfx_1            - gradient at the trial point
+
    fx_0              - objective value at the initial point
−
        dir              - search direction vector
+
−
        spin_system      - Spinach data structure with line
+
    fx_1              - objective value at the trial point
−
                            search settings in control
+
−
    Returns:
+
    gfx_0            - gradient at the initial point
−
        test              - logical true if the selected
+
−
                            condition is satisfied
+
    gfx_1            - gradient at the trial point
 +
 +
    dir              - search direction vector
 +
 +
    spin_system      - Spinach data structure with line
 +
                        search settings in control
  
 
==Outputs==
 
==Outputs==
  
−
    this function produces output as described in source code
+
    test              - logical true if the selected
 +
                        condition is satisfied
  
 
==Examples==
 
==Examples==

Latest revision as of 06:30, 30 August 2026

Applies one of the line search acceptance tests used by the bracketing and sectioning routines in constrained optimisation and returns true when the chosen condition is satisfied.

Syntax

             test=alpha_conds(test_type,alpha,fx_0,fx_1,...
                              gfx_0,gfx_1,dir,spin_system)

Parameters

   test_type         - condition selector:

                       0 for monotonic increase test
                       1 for Armijo sufficient increase test
                       2 for strong Wolfe curvature test
                       3 for ascent direction test

   alpha             - trial step length

   fx_0              - objective value at the initial point

   fx_1              - objective value at the trial point

   gfx_0             - gradient at the initial point

   gfx_1             - gradient at the trial point

   dir               - search direction vector

   spin_system       - Spinach data structure with line
                       search settings in control

Outputs

   test              - logical true if the selected
                       condition is satisfied

Examples

See examples in the Spinach distribution relevant to this function.

Notes

This page was generated from the function header in the Spinach repository.

See also

bracketing.m, sectioning.m, cubic_interp.m, fmaxnewton.m, bfgs.m, aux_mat.m, dirdiff.m, drifts.m, ensemble.m, hess_reorder.m, objeval.m, optimcon.m, trapdiff.m, Optimal_control_module

Version 2.11, authors: David Goodwin, Ilya Kuprov