Initializing help system before first use

problem.getlpsol

Purpose
Used to obtain the LP solution values following optimization.
Synopsis
problem.getlpsol(x, slack, duals, djs)
Arguments
x 
Array to store the values of the primal variables. May be None if not required.
slack 
Array to store the values of the slack variables. May be None if not required.
duals 
Array to store the values of the dual variables ( cBTB-1). May be None if not required.
djs 
Array to store the reduced cost for each variable ( cT-cBTB-1A). May be None if not required.
Example
The following sequence of function calls will get the LP solution ( x) at the top node of a MIP and the optimal MIP solution ( y): 
p.mipoptimize("l") # only solve the LP relaxation
x = []
p.getlpsol(x)
print("root LP solution:", x)
p.mipoptimize() # solve the MIP problem
x = p.getSolution()
print("final MIP solution", x)
Further information
1. After solving an LP, it is recommended to use problem.getSolution to retrieve the solution.
2. When an integer solution is found during a tree search, it is always set up as a solution to the current node; therefore the integer solution is available as the current node. It is recommended to retrieved the solution with problem.getCallbackSolution and problem.getCallbackPresolveSolution.
3. If the problem is modified after calling lpoptimize, then the solution will no longer be available.
4. If the problem has been presolved, then getlpsol returns the solution to the original problem. The only way to obtain the presolved solution is to call the related function, problem.getpresolvesol.
Related topics
problem.getSolution, problem.getCallbackSolution, problem.getCallbackPresolveSolution, problem.writeprtsol, problem.writesol.

Parent Topic Xpress problem methods

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