KNITRO
Robust and powerful solver for non-linear optimization and large complex problem solving
Nonlinear optimization problems arise in numerous business and industry applications. KNITRO non-linear solver delivers high performing and robust optimization solutions for the most challenging applications. Many customers and hundreds of sites worldwide rely on KNITRO to deliver optimization excellence for various financial, energy, communications, science and engineering applications.
KNITRO is developed by Ziena Optimization. Artelys distributes and provides support worldwide. Ziena was founded in 2001 by world-renowned scientists from Northwestern University to provide robust software tools and responsive professional technical support for difficult nonlinear optimization problems. Artelys distributes and supports worldwide the nonlinear optimization package KNITRO either as a standalone component or with the AMPL modelling environment. Artelys also provides additional modelling and integration services.
The most advanced optimization techniques
KNITRO, which uses the most recent optimization techniques, is an ideal tool for solving problems, such as pricing or revenue management, parameter identification in financial and industrial models, or design and operation of electricity and gas transportation networks. It can efficiently handle nonconvex nonlinear models with thousands of variables. KNITRO is the first nonlinear optimization package to offer two options, "interior points" and "active set", for the solution of inequality constrained problems; this reinforces its efficiency on a wide range of models with different structures.
Academic Partnership
Artelys and Ziena Optimization offer partnership programs with universities and other public training and research centres. These partnerships aim at promoting teaching and research in optimization. Academic partners get KNITRO and AMPL licenses at discounted prices.
For further information on academic partnership, please contact us.
Features
Unique solver able to solve a wide range of problems
The optimization techniques used by KNITRO offer the leading combination of computational efficiency and robustness. KNITRO is the only solver with three different algorithms, allowing it to solve a large range of complex problems.
Problems classes solved by KNITRO
• General Nonlinear Constrained Problems (NLP), including Nonconvex
• Linear Problems (LP)
• Quadratic Programming Problems (QP), Both Convex and Nonconvex
• Least Squares Problems/Regression, Both Linear and Nonlinear
• Systems of Nonlinear Equations
• Mathematical Programs with Complementarity Constraints (MPCCs/MPECs)
• Mixed Integer Nonlinear Problems (MIP/MINLP)
Key features
• Efficient and Robust Solution for Large-Scale Problems
• Both Interior-Point (Barrier) and Active-Set Solvers
• Derivative-free, 1st-Derivative and 2nd-Derivative Options
• Multi-Start Feature for Seeking the Global Solution
• Options to Remain Feasible throughout the Optimization
• Both Iterative and Direct Approaches for Computing Newton-like Steps
Programming interfaces
Modelling language interfaces
Operating Systems
Examples and applications
KNITRO is used in commercial financial applications for…
• Portfolio Optimization
• Optimal Pricing ? Risk Management
• Credit Risk
• Strategic Bidding and Auctions (Nash equilibrium)
• Demand Optimization
• Nonlinear Least Squares (data fitting)
KNITRO and the Energy sector
KNITRO is used in various power transmission problems…
• Nonlinear OPF (optimal power flow) problem
• Optimize generator costs & line losses
• Nonlinear AC power flow equations
• Transmission and other technical constraints
User manuals
KNITRO version 8.0 is described in the user manual: KNITRO 8.0 User's Manual, December 2011.
Older releases:
• KNITRO 7.0
• KNITRO 6.0
• KNITRO 5.2
• KNITRO 5.1
• KNITRO 5.0
Ziena License Manager User
Download a trial version
Frequently asked questions
In this section, there is a selection of general issues encountered during the installation and the use of KNITRO and our answers to help you. For specific help please contact us.
Q : What should I do to purchase KNITRO?
A : Please contact KNITRO sales team.
Q: What should I do when I have difficulties installing KNITRO?
A: Read section 1.3 and 1.4 (Installation and Troubleshooting) of the user manual (html link). If you cannot resolve your problem, please contact KNITRO support team (for users under maintenance only).
Q: What should I do to make KNITRO solves my problem faster?
A: Read section 2.15 (Tips and Tricks) of the user manual (html link). If you cannot resolve your problem, please contact KNITRO support team (for users under maintenance only).
Q : How do I get KNITRO 8.0 behaves similarly to KNITRO 7.0?
A : KNITRO 8.0 can behave more like KNITRO 7.0 by setting the following non-default options in KNITRO 8.0: presolve=0, bar_switchrule=0.
Q : How do I get KNITRO 7.0 behaves similarly to KNITRO 6.0?
A : KNITRO 7.0 can behave more like KNITRO 6.0 by setting the following non-default options in KNITRO 7.0: blasoption=0, linsolver=4, bar_directinterval=some very large number (e.g. 10000).
KNITRO support
Artelys provides technical assistance worldwide for KNITRO either as a standalone component or with AMPL modelling environment.
More informationKNITRO support
Artelys provides technical assistance worldwide for KNITRO either as a standalone component or with AMPL modeling environment.
The Annual License Maintenance Service (ALMS) contract offers the following services:
Telephone and e-mail assistance for the use of KNITRO or AMPL if necessary. This assistance is ensured by Artelys. Help with modeling is excluded, but Artelys provides you with useful information and advices to benefit from the numerical performances and all the functionalities of KNITRO.
Free and automatic upgrade of your KNITRO and AMPL software. Ziena Optimization, which develops KNITRO, is committed to maintain it at the leading edge of optimization technology. ALMS holders automatically receive all significant enhancements.
Privileged access to new services and products.
For any technical problem or commercial information, please contact us at +33 (0)1 44 77 89 00 or use our contact page.
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