Difference between revisions of "Sectioning.m"
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{{DISPLAYTITLE:sectioning.m}} __NOTOC__ | {{DISPLAYTITLE:sectioning.m}} __NOTOC__ | ||
| − | Refines a previously found step bracket by repeated cubic interpolation until a step satisfying Wolfe tests is found | + | Refines a previously found step bracket by repeated cubic interpolation until a step satisfying Wolfe tests is found or the bracket collapses below numerical accuracy. |
==Syntax== | ==Syntax== | ||
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dir,data,spin_system) | dir,data,spin_system) | ||
| − | == | + | ==Parameters== |
cost_function - objective function handle | cost_function - objective function handle | ||
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==See also== | ==See also== | ||
| − | + | [[bracketing.m]], [[alpha_conds.m]], [[cubic_interp.m]], [[fmaxnewton.m]], [[bfgs.m]], [[bfgs_upd.m]], [[hessreg.m]], [[lbfgs.m]], [[Optimal_control_module]] | |
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''Version 2.11, authors: David Goodwin, [[Ilya Kuprov]]'' | ''Version 2.11, authors: David Goodwin, [[Ilya Kuprov]]'' | ||
Latest revision as of 19:41, 6 June 2026
Refines a previously found step bracket by repeated cubic interpolation until a step satisfying Wolfe tests is found or the bracket collapses below numerical accuracy.
Syntax
[alpha,fx_1,gfx_1,exitflag,data]=...
sectioning(cost_function,A,B,x_0,fx_0,gfx_0,...
dir,data,spin_system)
Parameters
cost_function - objective function handle
a - lower bracket structure with
fields alpha, fx, and gfx
b - upper bracket structure with
fields alpha, fx, and gfx
x_0 - current optimisation vector
fx_0 - objective value at x_0
gfx_0 - gradient at x_0
dir - search direction vector
data - optimisation workspace structure
spin_system - Spinach data structure with
sectioning settings
Returns:
alpha - accepted step length
fx_1 - objective value at alpha
gfx_1 - gradient at alpha
exitflag - 0 on success, -2 on failure
data - updated optimisation workspace
Outputs
this function produces output as described in source code
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, alpha_conds.m, cubic_interp.m, fmaxnewton.m, bfgs.m, bfgs_upd.m, hessreg.m, lbfgs.m, Optimal_control_module
Version 2.11, authors: David Goodwin, Ilya Kuprov
