Questions tagged [xpress-optimizer]
32 questions
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How to correctly define a quadratic constraint on xpress
I'm implementing on Xpress a problem with different solution proposed on a paper. The idea is to decompose a matrix X into a convex sum of 0 1 matrices.
Among the constraints of the problem, the previous one can be written as:
equations = []
for i…
Davide Trono
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Warnings observed when trying to solve NLP, MINLP and SOCP using FICO Xpress
[1]I'm are trying to solve NLP, MINLP and SOCP using the licensed version of FICO Xpress, but I'm facing this warning. Can you help me out with this issue?
Also I'm using opt=SolverFactory('xpress') to call the solver.
[1]:…
adithya ganesh
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ufunc 'subtract' not supported for the input types....inputs could not be safely coerced to any supported types according to the casting rule ''safe''
import numpy as np
import xpress as xp
p = xp.problem ("Problem")
x = np.empty(6+1).tolist()
constraint = np.array([140,100,110,100,120,100], dtype = xp.npvar)
for i in range(6):
x[i] = x[i] <= constraint
p.addConstraint(x[i])
y =…
prince Dao-ayan
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Xpress Mosel Parallel Solving
Is it possible to have two submodles (.mos) running in parallel as input data for a master problem?
Is it correct to repeat twice the next code, one for each sub model? Because I have one bim file for each sub model, in my case 2 bim…
Ana Vaz
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MISDP/MISOCP in cvxpy
I'm trying to solve the following problem in CVXPY.
The problem is a mixed-integer SDP due to the PSD matrix we're solving. However, according to this list it looks as though none of the solvers can handle such a problem.
Can we use the fact that A…
Richard
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Julia Jump Xpress.jl XPRESSDIR environment variable for installation
In my .zshenv I've tried adding an environment variable by adding the following line
export XPRESSDIR='/Applications/FICO\ Xpress/Xpress\ Workbench.app/Contents/Resources/xpressmp'
I've also tried
export XPRESSDIR='/Applications/FICO\…
montoisky
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2 answers
TypeError: 'int' object is not callable, assigning equal names to diff variables?
I've been at this problem for a few hours now, I seem to have named an integer variable and a function the same but I just don't know which variable/function I am assigning the same name to. Here's the function where the error occurs:
def…
Taken Spark
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How Can I declare constraints in Xpress IVE?
I am trying to write a model in Xpress IVE however I got
error101: Incompatible types for operator ('mpvar' * 'mpvar' not defined). error.
I tried to write this constraint but I couldn't make it.
The two consecutive characters on the string must be…
Whitlock
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(FICO Xpress) Is it possible to specify the number of positive and negative results I would like to get via constraints?
I am currently trying to create a model where the results of the objective function when applied to all rows in the problem will be used for recommendation purposes.
…
Daniel Coben
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Optimization results from xpress do not follow the specified variable type
I found some problems where the optimization result from xpress does not follow the specified variable type. I set vartype=xp.binary when I create the xpress variables, but some of the results have values such as 0.13333, 0.36667, 0.5.
I found that…
Starz
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0
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1 answer
Xpress Mosel returning zeroes for all rows
I am an absolute beginner at Xpress Mosel and Linear Programming in general so please forgive me if I made any obvious mistakes. That being said, I am currently in the process of making up a problem and implementing it in Xpress Workbench.
The…
Daniel Coben
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1 answer
Shadow price - XPRESS - Pulp
I am trying to obtain the shadow price of a LP problem using Pulp and the XPRESS solver.
With the CBC solver, the .pi command works fine :
import pulp
my_lp_problem = pulp.LpProblem("My LP Problem", pulp.LpMinimize)
a =…
TMart
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MIP Solvers contradict each other
I am solving a model with GAMS/CPLEX and CPLEX claims it to be infeasible. The same behaviour shows the solver BDMLP.
I am solving the exact same model with GAMS/XPRESS and it provides the (known) optimal solution. The solvers BONMIN and CBC solve…
Clement
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How to use Fico Xpress (Mosel) with Java?
I have created an optimization model with Xpress and now I want to access it via my Java code.
On the official Xpress Help page (https://www.fico.com/fico-xpress-optimization/docs/dms2019-01/mosel/UG/dhtml/moselugC2_sec_secc2java.html) it said to…
niko
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2 answers
How to set stop criteria for integer programming optimization in yalmip/matlab with xpress solver
I have an integer programming optimization problem, that I solve in matlab using yalmip and xpress as the solver. For the solver I want to set two stopping criteria - a time limit and an optimal gap limit.
I have tried to use the xpress functions…
Mike Lang
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