e04rxf adds an additional means of communication to routines within the NAG optimization modelling suite. It allows you to either read or write a piece of information in the handle in the form of a real array. The item is identified by
cmdstr and the direction of the communication is set by
ioflag.
The functionality is supported by all solvers within the NAG optimization modelling suite for the retrieval of their final solutions.
e04rxf, moreover, can also be used by a selection of the solvers in the NAG Library, such as,
e04mtf and
e04ptf for the retrieval of the approximate solutions within the monitoring step. See the documentation of the individual solvers. In addition, you can retrieve solutions from a specific solver by adding the solver name after the available
cmdstr mentioned above, e.g., keywords
X e04mt or
X handle_solve_lp_ipm return the value of primal variables only from the linear programming solver
e04mtf. This is useful when a problem is solved by several different solvers. See
Section 3.1 in the
E04 Chapter Introduction for more details about the NAG optimization modelling suite.
None.
If on entry
or
, explanatory error messages are output on the current error message unit (as defined by
x04aaf).
Not applicable.
Background information to multithreading can be found in the
Multithreading documentation.
Please consult the
X06 Chapter Introduction for information on how to control and interrogate the OpenMP environment used within this routine. Please also consult the
Users' Note for your implementation for any additional implementation-specific information.
None.
This example demonstrates how to use
e04rxf to extract the current approximation of the solution when the monitoring routine
monit is called during the solve by
e04mtf.
We solve the following linear programming problem:
subject to the bounds
and the general constraints
During the monitoring step of
e04mtf, if the three convergence measures are below an acceptable threshold, the approximate solution is extracted with
e04rxf and printed on the standard output.