Hi,
It is not very what you mean here. But I can guide you to the Analysis VI.
It is Program Files/National Instruments/Labview 6/vi.lib/Analysis
This folder contains a set of Analysis related LLBs.
Regarding the user selecting the type of Analysis during run time, you can get it either by using a ring menu and a corresponding case structure in the block diagram.
You can take a look at the examples on Ring menu Control.
Please let me know if this helps.
LabVIEW