prev function

prev(N)

Returns the value of this element itself, N time steps ago. See last, for a function that returns a previous value of any element other than this one itself.

**Input**: numeric

**Result**: numeric

**Example**:

Consider a variable that flips from state 1 to state 2 when some triggering condition is satisfied (the Boolean variable, trigger, is true, for example) then stays in state 2. The equation for the variable could make use of prev, as follows:

if time()==0 then 1 elseif trigger then 2 else prev(1)

In: Contents >> Working with equations >> Functions >> Built-in functions