Calculates from a time parameter and a percentage a value for the amount of a value that remains after 1 period of time
half_life_factor(t, p = 0.5)
| t | A number, the time it takes for an initial value to decay to `p`% of the original value |
|---|---|
| p | A number, the percentage to reduce to (defaults to 50%) |
A value in \[0, 1\] that is the percentage that would remain after 1 time period elapses