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===Discrete time===
Discrete time makes use of [[difference equation]]sequations, also known as recurrence relations. An example, known as the [[logistic map]] or logistic equation, is
:
:<math> x_{t+1} = rx_t(1-x_t),</math>
in which ''r'' is a [[Parameter#Mathematical functions|parameter]] in the range from 2 to 4 inclusive, and ''x'' is a variable in the range from 0 to 1 inclusive whose value in period ''t'' [[nonlinearity|nonlinearly]] affects its value in the next period, ''t''+1. For example, if <math>r=4</math> and <math>x_1 = 1/3</math>, then for ''t''=1 we have <math>x_2=4(1/3)(2/3)=8/9</math>, and for ''t''=2 we have <math>x_3=4(8/9)(1/9)=32/81</math>.
Another example models the adjustment of a [[price]] ''P'' in response to non-zero [[excess demand]] for a product as
:
:<math>P_{t+1} = P_t + \delta \cdot f(P_t,...)</math>
where <math>\delta</math> is the positive speed-of-adjustment parameter which is less than or equal to 1, and where <math>f</math> is the [[excess demand function]].
===Continuous time===
Continuous time makes use of [[differential equation]]sequations. For example, the adjustment of a price ''P'' in response to non-zero excess demand for a product can be modeled in continuous time as
:
:<math>\frac{dP}{dt}=\lambda \cdot f(P,...)</math>
where the left side is the [[first derivative]] of the price with respect to time (that is, the rate of change of the price), <math>\lambda</math> is the speed-of-adjustment parameter which can be any positive finite number, and <math>f</math> is again the excess demand function.
==Graphical depiction==
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