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==[[Causality_OldKiwi]]== | ==[[Causality_OldKiwi]]== | ||
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| + | A causal system has outputs that only depend on current and/or previous inputs. | ||
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| + | *Example of a '''causal''' system: | ||
| + | <math>y(t) = x(t) + x(t - 1)</math> | ||
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| + | *Example of a '''non-causal''' system: | ||
| + | <math>y(t) = x(t) + x(t + 1)</math> | ||
==[[Stability_OldKiwi]]== | ==[[Stability_OldKiwi]]== | ||
Revision as of 22:54, 17 June 2008
Contents
The six basic properties of Systems_OldKiwi
Memory_OldKiwi
A system with memory has outputs that depend on previous (or future) inputs.
- Example of a system with memory:
$ y(t) = x(t - \pi) $
- Example of a system without memory:
$ y(t) = x(t) $
Invertibility_OldKiwi
An invertible system is one in which there is a one-to-one correlation between inputs and outputs.
- Example of an invertible system:
$ y(t) = x(t) $
- Example of a non-invertible system:
$ y(t) = |x(t)| $
In the second example, both x(t) = -3 and x(t) = 3 yield the same result.
Causality_OldKiwi
A causal system has outputs that only depend on current and/or previous inputs.
- Example of a causal system:
$ y(t) = x(t) + x(t - 1) $
- Example of a non-causal system:
$ y(t) = x(t) + x(t + 1) $
