orbit: Calculate visible path of celestial object at given location

Description Usage Arguments Examples

View source: R/mechanics.R

Description

This function calculates the visible path of a celestial object from any location on earth. It outputs a skyscapeR.orbit object, which includes AZ and ALT information.

Usage

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orbit(dec, loc, res = 0.25, refraction = T, ...)

Arguments

dec

Declination of object.

loc

Location, either a skyscapeR.object or a vector containing the latitude and longitude of location, in this order.

res

The resolution (in degrees of RA) with which to calculate the path.

refraction

(Optional) If set to TRUE it will calculate apparent rather than true altitudes. Default is TRUE.

...

Any other parameters to be passed unto swe_azalt.

Examples

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# Visible path of sun on June Solstice on year 3999 BC from London:
sun.dec <- jS(-4000)
london.lat <- 51.5074 #N
london.lon <- -0.1278 #W
loc <- c( london.lat, london.lon )
path <- orbit(sun.dec, loc)
plot(path$az, path$alt, ylim=c(0,90), type='l', xlab='AZ', ylab='ALT', col='red', lwd=2)

f-silva-archaeo/skyscapeR documentation built on Jan. 22, 2019, 8:11 a.m.