@ke, the t_tide package includes may functions including t_tide.m. The code for t_tide.m has extensive comments describing its inputs and outputs. For t_tide, the one required input is a time series - in other words, a vector or array of observed values at regular untervals (assumed to be 1 hour by default, but you can specify an alternative interval). The time series could be water elevations, water pressures, or current velocities (expressed as complex numbers), for example. There are various optional arguments, all described in the comments of t_tide.m.
See the article describing the t_tide package, here, for a more complete description. You should be able to access the full article via your university library.
Sounds like a good assignment. Good luck.
