lambdas {TideHarmonics}

Calculates Astronomical Longitudes

Description

Calculates astronomical longitudes for given days. Mainly for internal use.

Usage

  lambdas(dvec, astlon = c("task","cartwright"), ...)  

Arguments

dvec

A vector of days. Should be a Date object or an object that can be converted to a Date object.

astlon

The longitude formula to be used. The default "task" is the formulas use in the TASK-2000 software. The alternative "cartwright" uses Cartwright(1982).

...

Passed to the as.Date function.

Value

A numeric matrix. Values are in degrees and given in the interval [0,360]. The rows represent astronomical periods of increasing length: sidereal month (s), tropical year (h), lunar perigee (p), lunar nodal (N), sun's perihelion (ph). These correspond to the last five Doodson numbers.

See Also

ftide, harmonics

Examples

days <- seq(as.Date("2012-12-30"), as.Date("2013-01-08"), 1)
lambdas(days)