Computational steering is the practice of manually intervening with an otherwise autonomous

computational process Computation is any type of arithmetic or non-arithmetic calculation that follows a well-defined model (e.g., an algorithm). Mechanical or electronic devices (or, historically, people) that perform computations are known as ''computers''. An espe ...

, to change its outcome. The term is commonly used within the

numerical simulation Computer simulation is the process of mathematical modelling, performed on a computer, which is designed to predict the behaviour of, or the outcome of, a real-world or physical system. The reliability of some mathematical models can be deter ...

community, where it more specifically refers to the practice of interactively guiding a computational experiment into some region of interest.

Examples

A simple, but contrived, example of computational steering is: * In a simulated chess match with two automated players: manually forcing a certain move at a particular time for one player, to change the evolution of the game. Some real examples of computational steering are: * In a

population dynamics Population dynamics is the type of mathematics used to model and study the size and age composition of populations as dynamical systems. History Population dynamics has traditionally been the dominant branch of mathematical biology, which has ...

simulation: changing selection pressures exerted between hosts and parasites, to examine the effect on their coevolution. * In a

fluid dynamics In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids—liquids and gases. It has several subdisciplines, including '' aerodynamics'' (the study of air and other gases in motion) ...

simulation: resetting the phase state of an immiscible fluid, to speed the search for its critical separation temperature.

System design

Computational steering systems are a manner of feedback

control system A control system manages, commands, directs, or regulates the behavior of other devices or systems using control loops. It can range from a single home heating controller using a thermostat controlling a domestic boiler to large industrial ...

, where some or all of the

feedback Feedback occurs when outputs of a system are routed back as inputs as part of a chain of cause-and-effect that forms a circuit or loop. The system can then be said to ''feed back'' into itself. The notion of cause-and-effect has to be handled ...

is provided interactively by the operator. All computational steering mechanisms have three fundamental components: * A target system that is being studied * A representation of the target system, typically a graphical visualization, that can be perceived by the investigator * A set of controls that the investigator can use to provide feedback that modifies the state, behavior, or product of the system being studied

Disambiguation

There appears to be a distinction that the term ''computational steering'' is used only when referring to interaction with simulated systems, not operational ones. Further clarification on this point is needed. For example: Vetter (who is apparently well acquainted with the computational steering field ) refers to the following practice as ''interactive steering''. * In a

grid computing Grid computing is the use of widely distributed computer resources to reach a common goal. A computing grid can be thought of as a distributed system with non-interactive workloads that involve many files. Grid computing is distinguished from ...

framework: adjusting the cache size of a computational process, to examine the effect on its performance.

Computational steering software

* SCIRun
Cumulvs

RealityGrid

References

Control engineering Simulation software Computational science {{simulation-software-stub