I am new to LabVIEW and needed to create a sort of look up array where user feeds in a numerical value and get a particular row as a result. If you look at the attached vi, I have a pre-defined array for port, position and polarization corresponding to discrete wavelength values. If user types in a wavelength value from 0-1000, output fetches corresponding other 3 quantities. I want to allow users to feed in between values for example 110 as wavelength and get interpolated values for position and polarization. However, port number cannot be an interpolated value as it has to be a fixed number. Can anyone show me a way to do this?