Editing Computer simulation (section)

== In practical contexts ==
{{More citations needed section|date=June 2022}}
Computer simulations are used in a wide variety of practical contexts, such as:
* analysis of [[air pollutant]] dispersion using [[atmospheric dispersion modeling]]
* As a possible humane alternative to live [[animal testing]] in respect to [[animal rights]].
* design of complex systems such as [[aircraft]] and also [[logistics]] systems.
* design of [[noise barrier]]s to effect roadway [[noise mitigation]]
* modeling of [[Application performance management|application performance]]<ref>{{cite book | last = Wescott | first = Bob | title = The Every Computer Performance Book, Chapter 7: Modeling Computer Performance | publisher = [[CreateSpace]] | date = 2013 | isbn = 978-1482657753 | url = https://books.google.com/books?id=0SD1mgEACAAJ}}</ref>
* [[flight simulator]]s to train pilots
* [[Atmospheric model|weather forecasting]]
* [[risk management|forecasting of risk]]
* simulation of electrical circuits
* [[Power system simulation]]
* simulation of other computers is [[Emulator|emulation]].
* forecasting of prices on financial markets (for example [[Adaptive Modeler]])
* behavior of structures (such as buildings and industrial parts) under stress and other conditions
* design of industrial processes, such as chemical processing plants
* [[strategic management]] and [[organizational studies]]
* [[reservoir simulation]] for the petroleum engineering to model the subsurface reservoir
* process engineering simulation tools.
* [[Robotics suite|robot simulators]] for the design of robots and robot control algorithms
* [[UrbanSim|urban simulation models]] that simulate dynamic patterns of urban development and responses to urban land use and transportation policies.
* [[Traffic engineering (transportation)|traffic engineering]] to plan or redesign parts of the street network from single junctions over cities to a national highway network to transportation system planning, design and operations. See a more detailed article on [[Traffic Simulation|Simulation in Transportation]].
* modeling car crashes to test safety mechanisms in new vehicle models.
* [[Theoretical production ecology|crop-soil systems]] in agriculture, via dedicated software frameworks (e.g. [[BioMA]], OMS3, APSIM)

The reliability and the trust people put in computer simulations depends on the [[Validity (logic)|validity]] of the simulation [[model (abstract)|model]], therefore [[verification and validation]] are of crucial importance in the development of computer simulations. Another important aspect of computer simulations is that of reproducibility of the results, meaning that a simulation model should not provide a different answer for each execution. Although this might seem obvious, this is a special point of attention{{Editorializing|date=December 2022}} in [[stochastic simulation]]s, where random numbers should actually be semi-random numbers. An exception to reproducibility are human-in-the-loop simulations such as flight simulations and [[computer games]]. Here a human is part of the simulation and thus influences the outcome in a way that is hard, if not impossible, to reproduce exactly.

[[Vehicle]] manufacturers make use of computer simulation to test safety features in new designs. By building a copy of the car in a physics simulation environment, they can save the hundreds of thousands of dollars that would otherwise be required to build and test a unique prototype. Engineers can step through the simulation milliseconds at a time to determine the exact stresses being put upon each section of the prototype.<ref>Baase, Sara. A Gift of Fire: Social, Legal, and Ethical Issues for Computing and the Internet. 3. Upper Saddle River: Prentice Hall, 2007. Pages 363–364. {{ISBN|0-13-600848-8}}.</ref>

[[Computer graphics]] can be used to display the results of a computer simulation. [[Animations]] can be used to experience a simulation in real-time, e.g., in [[Training Simulation|training simulations]]. In some cases animations may also be useful in faster than real-time or even slower than real-time modes. For example, faster than real-time animations can be useful in visualizing the buildup of queues in the simulation of humans evacuating a building. Furthermore, simulation results are often aggregated into static images using various ways of [[scientific visualization]].

In debugging, simulating a program execution under test (rather than executing natively) can detect far more errors than the hardware itself can detect and, at the same time, log useful debugging information such as instruction trace, memory alterations and instruction counts. This technique can also detect [[buffer overflow]] and similar "hard to detect" errors as well as produce performance information and [[Performance tuning|tuning]] data.