How to build a graph with more than one y variable, same x, with 64 bit real data, not in an array, with out clearing each time.

I want  to build a graph with more than one y variable, same x, with 64 bit real data, not in an array, with out clearing each time it updates, in order to track data while it is being collected. It'd be nice if the different y variables could be different colors too.