The tidedata dataset contains Tide-constituent information that is use by tidem() to fit tidal models. tidedata is a list containing


a list containing vectors name (a string with constituent name), freq (the frequency, in cycles per hour), kmpr (a string naming the comparison constituent, blank if there is none), ikmpr (index of comparison constituent, or 0 if there is none), df (frequency difference between constituent and its comparison, used in the Rayleigh criterion), d1 through d6 (the first through sixth Doodson numbers), semi, nsat (number of satellite constituents), ishallow, nshallow, doodsonamp, and doodsonspecies.


a list containing vectors deldood, phcorr, amprat, ilatfac, and iconst.


a list containing vectors iconst, coef, and iname.

Apart from the use of d1 through d6, the naming and content follows T_TIDE (see Pawlowicz et al. 2002), which in turn builds upon the analysis of Foreman (1978).


The data come from the tide3.dat file of the T_TIDE package (Pawlowicz et al., 2002), and derive from Appendices provided by Foreman (1978). The data are scanned using tests/tide.R in this package, which also performs some tests using T_TIDE values as a reference.


Foreman, M. G. G., 1978. Manual for Tidal Currents Analysis and Prediction. Pacific Marine Science Report. British Columbia, Canada: Institute of Ocean Sciences, Patricia Bay.

Pawlowicz, Rich, Bob Beardsley, and Steve Lentz, 2002. Classical tidal harmonic analysis including error estimates in MATLAB using T_TIDE. Computers and Geosciences, 28, 929-937.

See also


Dan Kelley