====OldValue====

The **OldValue** function is part of the [[Trigger]] class. 

It returns the //previous// data value from ARDI, where 'previous' means the values in the [[values]] array the last time your function was called.

These are in the order that you specified in the '[[decorators|@data]]' decorator for your function.

The function has an //optional// parameter of the index in the array you'd like to read. If you don't specify, it assumes you want the 0th index. 

Note that if a previous event [[backtracing|can't be found]], these values might be **None**

===See Also===

You can also access the whole set of values using the [[oldvalues]] array.

You can see the //current// values for your points using the [[Value]] function or [[values]] array.