I think it would be useful to allow for more than just last() and prev(). I think you should get rid of prev() and add on to last(). I think the argument given to last(#) should not be ignored and used to go back in the history. That way it would be possible to use more than just 2 data points to force a trigger.
last(0) = the last data point
last(1) = the 2nd to last data point
last(2) = the 3rd to last data point
etc.
last(0) = the last data point
last(1) = the 2nd to last data point
last(2) = the 3rd to last data point
etc.
Comment