Computational steering is the practice of manually intervening with an otherwise autonomous
computational process
A computation is any type of arithmetic or non-arithmetic calculation that is well-defined. Common examples of computation are mathematical equation solving and the execution of computer algorithms.
Mechanical or electronic devices (or, historica ...
, to change its outcome. The term is commonly used within the
numerical simulation
Computer simulation is the running of a mathematical model on a computer, the model being designed to represent the behaviour of, or the outcome of, a real-world or physical system. The reliability of some mathematical models can be determin ...
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
Chess is a board game for two players. It is an abstract strategy game that involves no hidden information and no elements of chance. It is played on a square board consisting of 64 squares arranged in an 8×8 grid. The players, referred to as ...
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. Population dynamics is a branch of mathematical biology, and uses mathematical techniques such as differenti ...
simulation: changing selection pressures exerted between hosts and parasites, to examine the effect on their coevolution.
* In a
fluid dynamics
In physics, physical chemistry and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids – liquids and gases. It has several subdisciplines, including (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 handle ...
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 fro ...
framework: adjusting the cache size of a computational process, to examine the effect on its performance.
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Computational steering software
*
SCIRun
CumulvsRealityGrid
References
Control engineering
Simulation software
Computational science
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