Initializing help system before first use

Setting up and solving the problem

loadprob(objdef)

This procedure loads the currently-defined non-linear problem into the Xpress NonLinear optimization framework. This includes any purely linear part. Where a general constraint has a linear expression as its left or right hand side, that linear expression will be retained as linear relationships (constant coefficients) in the matrix. Thus, for example, in the anonymous constraint defining objdef, the objdef coefficient will be identified as a linear term and will appear as a separate item in the problem.

maximise

Optimization is carried out with the maximise or minimise procedures. They can take a string parameter – for example maxmimise("b") – as described in the Xpress NonLinear and Xpress Optimizer reference manuals.

With the default settings of the parameters, you will see usually nothing from the optimizer. The following parameters affect what is produced:

xnlp_verbose Normally set to false. If set to true, it produces standard Xpress NonLinear iteration logging.
xprs_verbose Normally set to false. If set to true, then information from the optimizer will also be output.
xslp_log Normally set to -1. If set to 0, limited information is output from the SLP iterations. Settings of 1 or greater produce progressively more information for each SLP iteration.
xslp_slplog If xslp_log is set to 0, this determines the frequency with which SLP progress is reported. The default is 10, which means that it prints every 10 SLP iterations.