# lambdas: Calculates Astronomical Longitudes In TideHarmonics: Harmonic Analysis of Tides

## Description

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

## Usage

 `1` ``` 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.

`ftide`, `harmonics`

## Examples

 ```1 2``` ```days <- seq(as.Date("2012-12-30"), as.Date("2013-01-08"), 1) lambdas(days) ```

### Example output

```         [,1]     [,2]     [,3]     [,4]     [,5]     [,6]     [,7]     [,8]
[1,] 120.0919 133.2683 146.4471 159.6235 172.7999 185.9763 199.1527 212.3291
[2,] 278.8420 279.8277 280.8123 281.7980 282.7836 283.7693 284.7549 285.7406
[3,] 252.1416 252.2530 252.3659 252.4773 252.5887 252.7001 252.8115 252.9229
[4,] 233.6972 233.6442 233.5899 233.5369 233.4840 233.4310 233.3781 233.3251
[5,] 283.1464 283.1464 283.1636 283.1636 283.1636 283.1636 283.1636 283.1636
[,9]    [,10]
[1,] 225.5055 238.6819
[2,] 286.7262 287.7119
[3,] 253.0343 253.1457
[4,] 233.2722 233.2192
[5,] 283.1636 283.1636
```

TideHarmonics documentation built on May 2, 2019, 6:34 a.m.