Feedback
Some basic and useful functions for modeling feedbacks.
Functions
| decay | Return the decay of a rate given a time interval. |
| growth | Return the growth of a rate given a time interval. |
decay
Return the decay of a rate given a time interval. The returned value can be directly multipled to compute the updated value applying the given decay.
Arguments
- #1: A decay rate per time unit. For example, a value of 0.2 means that there will be a decrease of 20% each time step.
- #2: A time interval or an Event. In the latter case, this function will use the Event's period as a time interval. The returning value is (1 - #1) ^ #2. For example, if the time interval is equals to one, the returning value will be one minus #1.
Usage
import("sci")
decay(0.5, 1) -- 0.5 (decay of 50% in one time step)
decay(0.1, 1/12) -- 10% per year in one month will be 0.99125 (reducing 0.875% per month)growth
Return the growth of a rate given a time interval. The returned value can be directly multipled to compute the updated value applying the given growth.
Arguments
- #1: A growth rate per time unit. For example, a value of 0.2 means that there will be 20% of growth each time step.
- #2: A time interval or an Event. In the latter case, this function will use the Event's period as a time interval. The returning value is (1 + #1) ^ #2. For example, if the time interval is equals to one, the returning value will be one plus #1.
Usage
import("sci")
growth(0.5, 1) -- 1.5 (growth of 50% in one time step)
growth(0.1, 1/12) -- 10% per year in one month will be 1.00797 (increasing 0.797% per month)