TK Solver
From Wikipedia, the free encyclopedia
TK Solver is a problem-solving programming environment developed by Universal Technical Systems, Inc. It has features common to many programming languages, spreadsheet, and numerical computing applications. It is marketed as a "mathematical modeling and knowledge-management system" and a "declarative object-based programming language."
Originally developed by Milos Konopasek and sold by Software Arts, the company behind VisiCalc - the world's first electronic spreadsheet, "TK Solver" was acquired by Universal Technical Systems after Software Arts fell into financial difficulty and was sold to Lotus Software.
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[edit] Core technology
TK Solver's core technologies are a declarative programming structure and an object-based interface. The interface, somewhat resembling that of a spreadsheet, comprises nine classes of objects:
- Rules: equations, formulas and logical statements
- Variables: numeric and non-numeric values, for input and output
- Units: all units conversion factors, in a single location
- Lists: ranges of numeric and non-numeric values, for data storage and for input and output
- Tables: groups of tables
- Plots: of ranges of data
- Functions: rule-based, list-based and procedural programming components
- Formats: for displaying numeric values
- Comments: for explanation and documentation
Each class of objects and their properties are summarized in and accessed from sheets -- Rule Sheet, Variable Sheet, Unit Sheet, etc. -- and subsheets. The interface uses toolbars and a hierarchal navigation bar that resembles the left side of the Windows Explorer.
The declarative programming structure is embodied in the two principal kinds of data on which solutions are based -- the rules and variables that in aggregate constitute the core of a mathematical model.
[edit] Rules, variables, and units
All rules are entered in the Rule Sheet. Unlike a spreadsheet or imperative programming environment, the rules can be in any order or sequence and are not expressed as assignment statements. "A + B = C / D" is a valid rule in TK Solver and can be solved for any of its four variables. Rules can be added and removed as needed in the Rule Sheet without regard for their order.
A TK Solver model can include up to 32,000 rules. Models can be incorporated in other models, and because of the declarative structure, rules and groups of rules can be used and reused as needed. The included TK Library contains more than 200 preprogrammed models—higher mathematics; statistics; engineering, scientific and financial models; and programming utilities.
Variables contained in a rule are automatically posted to the Variable Sheet when the rule is entered. The Variable Sheet contains columns for variable names, input values and output values. Any variable can operate as an input or an output. Depending on the choice of input and output variables, a model can be solved forward or backward.
With all unit conversion factors in one place in the Unit Sheet, units can be managed similarly to rules -- easily and conveniently added, deleted and shared among models. Conversion factors can be user input or selected from an extensive database organized into 32 categories. TK Solver solves models in a consistent set of "Calculation" units. Optionally, variables can be assigned "Display" units and TK automatically converts the values.
[edit] Problem-solving
TK Solver has several methods of solving: the Direct Solver, which works on the principle of consecutive substitution, and the Iterative Solver, which works on the principle of successive approximation starting from initial guess values for one or more unknown variables. There is also a list solver feature for solving over ranges of data: variables are associated with lists for input and output.
These features facilitate goal seeking and optimization. Included with the TK Solver Premium version is the Solution Optimizer, for direct setting of constraints.
[edit] User-defined functions
TK Solver models also incorporate built-in and user-defined functions. There are roughly 150 built-in functions: mathematical, trigonometric, Boolean, numerical calculus, database access, and programming functions, including string handling and calls to externally compiled routines. There are three types of user-defined functions: declarative rule functions; list functions, for table lookups and other operations involving pairs of lists; and procedure functions, for loops and other procedural operations which may also process or result in arrays.
[edit] Other features
Other objects—tables, plots, comments—turn a TK Solver model into a knowledge base. Models can be linked to other components with Microsoft Visual Basic and .NET tools. Models can also be Web-enabled, using another UTS product, RuleMaster. The TK Solver-Excel Toolkit links TK models and Excel spreadsheets. Standalone models can be created in the TK Solver Premium version, then opened in Excel or the free TK Player.
Another standard feature, MathLook, displays rules in two-dimensional mathematical notation, for debugging and documentation. Also included is the complete National Institute of Standards and Technology database of thermodynamic and transport properties, with built-in functions for accessing it. TK Solver is the platform for engineering applications marketed by UTS, including Integrated Gear Software, Interactive Roark’s Formulas, Heat Transfer on TK, and Dynamics and Vibration Analysis.
[edit] Alternatives
For small scale numerical analysis requirements, the goal-seeking and solver facilities in spreadsheets such as Microsoft Excel and Lotus 123 will often suffice, or you could try Eureka, a free solver that was once sold by Borland. The articles on numerical analysis, linear programming and constraint programming give other possible alternatives.
