XPRSgetlpsol

Purpose

Used to obtain the LP solution values following optimization.

Synopsis

int XPRS_CC XPRSgetlpsol(XPRSprob prob, double x[], double slack[], double dual[], double dj[]);

Arguments

prob	The current problem.
x	Double array of length COLS where the values of the primal variables will be returned. May be NULL if not required.
slack	Double array of length ROWS where the values of the slack variables will be returned. May be NULL if not required.
dual	Double array of length ROWS where the values of the dual variables ( c_B^TB^-1) will be returned. May be NULL if not required.
dj	Double array of length COLS where the reduced cost for each variable ( c^T-c_B^TB^-1A) will be returned. May be NULL if not required.

Example

The following sequence of commands will get the LP solution ( x) at the top node of a MIP and the optimal MIP solution ( y):

int cols;
double *x, *y;
...
XPRSmipoptimize(prob,"l");
XPRSgetintattrib(prob,XPRS_ORIGINALCOLS,&cols);
x = malloc(cols*sizeof(double));
XPRSgetlpsol(prob,x,NULL,NULL,NULL);
XPRSmipoptimize(prob,"");
y = malloc(cols*sizeof(double));
XPRSgetmipsol(prob,y,NULL);

Further information

1. If called during a global callback the solution of the current node will be returned.

2. When an integer solution is found during a global search, it is always set up as a solution to the current node; therefore the integer solution is available as the current node solution and can be retrieved with XPRSgetlpsol and XPRSgetpresolvesol.

3. If the matrix is modified after calling XPRSlpoptimize, then the solution will no longer be available.

4. If the problem has been presolved, then XPRSgetlpsol returns the solution to the original problem. The only way to obtain the presolved solution is to call the related function, XPRSgetpresolvesol.

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XPRSgetlpsol

XPRSgetlpsol