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XPRBsetvardir

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Purpose

Set a branching directive for a variable.

Synopsis

int XPRBsetvardir(XPRBvar var, int type, double c);

Arguments

var	BCL reference to a variable.
type	Directive type, which must be one of: XPRB_PR  priority; XPRB_UP  first branch upwards; XPRB_DN  first branch downwards; XPRB_PU  pseudo cost on branching upwards; XPRB_PD  pseudo cost on branching downwards.
c	An argument dependent on the type of directive to be defined. Must be one of: XPRB_PR  priority value — an integer between 1 (highest) and 1000 (least priority), the default; XPRB_UP  no input required — set to any value, e.g. 0; XPRB_DN  no input required — set to any value, e.g. 0; XPRB_PU  value of the pseudo cost on branching upwards; XPRB_PD  value of the pseudo cost on branching downwards.

Return value

0 if function executed successfully, 1 otherwise.

Example

The following example gives a priority of 10 to variable x1 and sets the preferred branching direction to be upwards.

XPRBprob prob;
XPRBvar x1;
 ...
x1 = XPRBnewvar(prob, XPRB_UI, "abc3", 0, 100);
XPRBsetvardir(x1, XPRB_PR, 10);
XPRBsetvardir(x1, XPRB_UP, 0);

Further information

1. This function sets any type of branching directive available in Xpress-MP. This may be a priority for branching on a variable (type XPRB_PR), the preferred branching direction (types XPRB_UP, XPRB_DN) or the estimated cost incurred when branching on a variable (types XPRB_PU, XPRB_PD). Several directives of different types may be set for a single variable.

2. Note that it is only possibly to set branching directives for discrete variables (including semi-continuous and partial integer variables). Function XPRBsetsosdir may be used to set a directive for a SOS.

Related topics

XPRBcleardir, XPRBsetsosdir.

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