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scbc2 [2014/09/09 07:06] – [Accuracy versus precision] simonw7 | scbc2 [2022/07/21 06:59] (current) – external edit 127.0.0.1 | ||
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+ | =====Some Computer Science Considerations===== | ||
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+ | In this session we explore what a model is, and how a simulation is different. | ||
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+ | ====Overall process of computational simulation==== | ||
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+ | "The overall problem solving process in computational simulation usually includes the following steps: | ||
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+ | - Develop a mathematical model -- usually expressed by equations of some type -- of a physical phenomena or system of interest. | ||
+ | - Develop algorithms to solve the equations numerically. | ||
+ | - Implement the algorithms in computer software. | ||
+ | - Run the software on a computer to simulate the physical process numerically. | ||
+ | - Represent the computed results in some comprehensible form such as graphical visualization. | ||
+ | - Interpret and validate the computed results, repeating any or all of the preceding steps, if necessary." | ||
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+ | (-- M. T. Heath. // | ||
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+ | All simulations are implemented with assumptions, | ||
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+ | //Some// sources of approximation: | ||
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+ | * modeling - for example, omitting friction | ||
+ | * empirical measurements - for examples, instruments have finite precision; noise; sample size | ||
+ | * previous computations - input or data may have come from other approximate computations | ||
+ | * truncation - for example, having to truncate an infinite series | ||
+ | * rounding - can only represent finite precision | ||
+ | * computer arithmetic | ||
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+ | (//Ibid//.) | ||
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+ | Also: | ||
+ | * limitations from using computers: | ||
+ | * binary representation of decimals | ||
+ | * [[ https:// | ||
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+ | ====Algorithmic (in)stability==== | ||
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+ | Even a " | ||
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+ | [[ http:// | ||
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+ | Particularly interesting exercises (pages 18-20, but 19-20): | ||
+ | [[ http:// | ||
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+ | ====Accuracy versus precision==== | ||
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+ | These words mean different things, though many scientists/ | ||
+ | distinct concepts; give thought to the " | ||
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+ | [[ http:// | ||
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+ | [[ http:// | ||
+ | // | ||
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+ | Which is more desirable: accuracy or precision? | ||
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+ | ====Working Environment / Tools==== | ||
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+ | ===Shell=== | ||
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+ | [[wiki: | ||
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+ | See also [[http:// | ||
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+ | [[http:// | ||
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+ | ===Make=== | ||
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+ | [[wiki: | ||
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