KNITRO
Robust and powerful solver for non-linear optimization and large complex problem solving
Non-linear optimization problems arise in numerous business and industry applications, such as optimizing a portfolio in the financial industry or getting the optimal pricing in the energy industry. Customers in hundreds of sites worldwide rely on KNITRO to deliver high performing and powerful optimization solutions for the most challenging applications in all industries: financial, energy, communications, science and engineering.
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 superior software tools and responsive professional technical support for difficult non-linear optimization problems.
KNITRO is available as a standalone component and with the AMPL modeling environment. Artelys provides additional modeling and integration services.
The most advanced optimization techniques
KNITRO 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 non-convex non-linear models with thousands of variables. KNITRO is the first non-linear optimization tool that offers two options for inequality constrained problems: "interior points" and "active set." These options reinforce the efficiency for a wide range of models with multiple structures.
Artelys and Ziena Optimization offer partnership programs with universities, public training and research centers to promote teaching and research in optimization. Academic partners get KNITRO and AMPL licenses at discounted prices.
For further information on academic partnership, please contact us.
Key benefits & Features
Key benefits
• Solve complex non-linear problems: handle large-scale, complex problems with millions of variables and constraints
• Offers the leading combination of computational efficiency and robustness
• Includes high accuracy solutions via the Active Set algorithm
• Offers the ability to choose the best algorithm among three options
• Flexibility of use
Key features
• Unique solver able to solve a wide range of problems
• Three different algorithmsBoth 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
Problems classes solved by KNITRO
• General Nonlinear Constrained Problems (NLP), including Non-convex
• Linear Problems (LP)
• Quadratic Programming Problems (QP), Both Convex and Non-convex
• 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)
Programming interfaces
Modelling language interfaces
Operating Systems
Business applications
KNITRO is used in all type of industries such as:
Financial industries:
• Portfolio optimization
• Optimal pricing and risk management
• Credit risk
• Strategic bidding and auctions (Nash equilibrium)
• Demand optimization
• Nonlinear least squares (data fitting)
The Energy sector:
KNITRO is used in various power transmission problems such as:
• Nonlinear OPF (optimal power flow) problem
• Optimize generator costs and line losses
• Nonlinear AC power flow equations
• Transmission and other technical constraints
Please feel free to contact us to receive more information regarding our business applications.
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
This section has 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. 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. If you cannot resolve your problem, please contact KNITRO support team (for users under maintenance only).
Q : How do I get KNITRO 8.0 to behave 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 to behave 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 worlwide 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 as necessary. This assistance is provided by Artelys. Help with modeling is excluded, but Artelys provides you with useful information and advices to help you benefit from the numerical performances and all the functionalities of KNITRO.
Free and automatic upgrades 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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