Initializing help system before first use

problem.getDuals

Purpose
Used to obtain the dual values associated with the incumbent solution during or after optimization with problem.optimize, problem.mipoptimize, problem.lpoptimize or problem.nlpoptimize.
Synopsis
duals = problem.getDuals(*constraints)
Argument
constraints 
(optional) constraint objects whose duals will be returned. If none is provided, a list of duals for all constraints in the problem will be returned.
Return value
duals 
A list of dual values if *constraints contains more than one constraint object or is not provided, a single dual value otherwise.
Example 
import xpress as xp
import numpy as np
p = xp.problem()
x = p.addVariables(10)
A = np.random.random((5,10))
b = np.random.random(5)
constr = xp.Dot(A,x) >= b
p.addConstraint(constr)
p.setObjective(xp.Sum(x))
p.optimize()
print("Duals of last two constraints:", p.getDuals(constr[-2:]))
Related topics
problem.getSolution, problem.getSlacks, problem.getRedCosts.

Parent Topic Xpress problem methods

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