e05jcc may be used to supply optional parameters to e05jbc from an external file. The initialization function e05jac must have been called before calling e05jcc.

2 Specification

#include <nag.h>

void	e05jcc (Nag_FileID fileid, Nag_E05State state, NagError fail)

The function may be called by the names: e05jcc or nag_glopt_bnd_mcs_optset_file.

3 Description

e05jcc may be used to supply values for optional parameters to e05jbc. e05jcc reads an external file which has been opened by a call to x04acc. Each line of the file defines a single optional parameter. It is only necessary to supply values for those arguments whose values are to be different from their default values.

Each optional parameter is defined by a single character string, consisting of one or more items. The items associated with a given optional parameter must be separated by spaces, or equals signs

[=]

. Alphabetic characters may be upper or lower case. The string

Static Limit = 100

is an example of a string used to set an optional parameter. For each optional parameter the string contains one or more of the following items:

–a mandatory keyword;
–a phrase that qualifies the keyword;
–a number that specifies an integer or real value. Such numbers may be up to $40$ contiguous characters.

Blank strings and comments are ignored. A comment begins with an asterisk (*) and all subsequent characters in the string are regarded as part of the comment.

The implied data type (character, integer or real) of each value to set must match that expected by the corresponding optional parameter.

The file containing the optional parameters must start with Begin and must finish with End. An example of a valid options file is:

Begin * Example options file
   Static Limit = 500 
End

Optional parameter settings are preserved following a call to e05jbc and so the keyword

Defaults

is provided to allow you to reset all the optional parameters to their default values before a subsequent call to e05jbc.

A complete list of optional parameters, their symbolic names and default values is given in Section 12 in e05jbc.

4 References

None.

5 Arguments

1: $fileid$ – Nag_FileID Input: On entry: the ID of the option file to be read, as returned by a call to x04acc.
2: $state$ – Nag_E05State * Communication Structure: state contains information required by other functions in this suite. You must not modify it directly in any way.
3: $fail$ – NagError * Input/Output: The NAG error argument (see Section 7 in the Introduction to the NAG Library CL Interface).

6 Error Indicators and Warnings

NE_ALLOC_FAIL: Dynamic memory allocation failed.
See Section 3.1.2 in the Introduction to the NAG Library CL Interface for further information.
NE_BAD_PARAM: On entry, argument $⟨ value ⟩$ had an illegal value.
NE_FILE_NOT_READ: At least one optional parameter from the options file could not be recognized. All optional parameters that were set from the file before this error was encountered will remain set on exit.

BEGIN found, but end-of-file found before END. All optional parameters that were set from the file before this error was encountered will remain set on exit.

Could not read options file.

End-of-file found before BEGIN.
NE_INTERNAL_ERROR: An internal error has occurred in this function. Check the function call and any array sizes. If the call is correct then please contact NAG for assistance.
See Section 7.5 in the Introduction to the NAG Library CL Interface for further information.
NE_NO_LICENCE: Your licence key may have expired or may not have been installed correctly.
See Section 8 in the Introduction to the NAG Library CL Interface for further information.
NE_NOT_INIT: Initialization function e05jac has not been called.
NE_NOT_PARSED: One of the numeric values to be set could not be parsed. Check that all such strings specify valid integer or real values.
NE_OUT_OF_RANGE: Attempt to assign an illegal value of $Local Searches$ ( $lcsrch$ ): $lcsrch = ⟨ value ⟩$ .

Attempt to assign an illegal value of $Repeatability$ ( $repeat$ ): $repeat = ⟨ value ⟩$ .

Attempt to assign a non-positive value of $Function Evaluations Limit$ ( $nf$ ): $nf = ⟨ value ⟩$ .

Attempt to assign a non-positive value of $Local Searches Limit$ ( $loclim$ ): $loclim = ⟨ value ⟩$ .

Attempt to assign a non-positive value of $Static Limit$ ( $stclim$ ): $stclim = ⟨ value ⟩$ .

Attempt to assign an out-of-bounds value of $Infinite Bound Size$ ( $infbnd$ ): $infbnd = ⟨ value ⟩$ .

Attempt to assign too small a value of $Local Searches Tolerance$ ( $loctol$ ): $loctol = ⟨ value ⟩$ .

Attempt to assign too small a value of $Target Objective Error$ ( $objerr$ ): $objerr = ⟨ value ⟩$ .

Attempt to assign too small a value of $Target Objective Safeguard$ ( $objsfg$ ): $objsfg = ⟨ value ⟩$ .

7 Accuracy

Not applicable.

8 Parallelism and Performance

Background information to multithreading can be found in the Multithreading documentation.

e05jcc is threaded by NAG for parallel execution in multithreaded implementations of the NAG Library.

Please consult the X06 Chapter Introduction for information on how to control and interrogate the OpenMP environment used within this function. Please also consult the Users' Note for your implementation for any additional implementation-specific information.

9 Further Comments

e05jdc, e05jec, e05jfc or e05jgc may also be used to supply optional parameters to e05jbc.

10 Example

This example finds the global minimum of the ‘peaks’ function in two dimensions

F (x, y) = 3 {(1 - x)}^{2} \exp (- x^{2} - {(y + 1)}^{2}) - 10 (\frac{x}{5} - x^{3} - y^{5}) \exp (- x^{2} - y^{2}) - \frac{1}{3} \exp (- {(x + 1)}^{2} - y^{2})

on the box

[−3, 3] \times [−3, 3]

The function

F

has several local minima and one global minimum in the given box. The global minimum is approximately located at

(0.23, - 1.63)

, where the function value is approximately

- 6.55

By specifying an initialization list via list, numpts and initpt we can start e05jbc looking close to one of the local minima and check that it really does move away from that point to one of the global minima.

More precisely, we choose

(−1, 0)

as our initial point (see Section 10.3), and let the initialization list be

(\begin{matrix} −3 & −1 & 3 \\ −3 & 0 & 3 \end{matrix}) .

This example solves the optimization problem using some of the optional parameters described in Section 12 in e05jbc.

e05jc: FL CL CPP AD PY MB

NAG CL Interfacee05jcc (bnd_​mcs_​optset_​file)

▸▿ Contents

1 Purpose

2 Specification

3 Description

4 References

5 Arguments

6 Error Indicators and Warnings

7 Accuracy

8 Parallelism and Performance

9 Further Comments

10 Example

10.1 Program Text

10.2 Program Data

10.3 Program Results

NAG CL Interface
e05jcc (bnd_mcs_optset_file)