track: Plot track of planets

In moonsun: Basic astronomical calculations with R

Description

To plot tracts of planets during to dates.

Usage

track(ephem, mag = 7, edge = 0.2, cex.star = 1,xlab = "Right Ascension",
           ylab = expression(paste("Declination", degree)), col.track = "red", 
          interval.lab = 15, lwd.track = 2, grid = TRUE, bright.lab = TRUE,
          bright, starcat,...) 

Arguments

ephem	Equatorial coordinates of celestial objects as generated. see planet for more information.
mag	Magnitude of stars to be plot on the background.
edge	Numeric, the edge extention of the plots from each side of the ploting margin.
cex.star	Numeric, indicating the point size of the stars to be ploted on the background.
xlab	label for the x axis.
ylab	label for the y axis.
col.track	color of the planet's track .
interval.lab	Time interval for the label.
lwd.track	Line width of the planet's track.
grid	Whether the grid of coordinate's should be drawn.
bright.lab	Whether to draw the labels of bright stars on the plot.
bright	Data frame for bright stars
starcat	Star catalogue used in plotting.
...	Other specified methods to draw the plot.

Details

User may employ this function when she/he wants to see the tracks of certain planet during time 1 to time 2. The input data should be generated by planet,or planet related functions such as mercury,mars,saturn. User may define her/his own celestral objects and plot the tracks using this function.

Value

NULL

Author(s)

Jinlong Zhang [e-mail]

References

http://www.clearskyinstitute.com/xephem/

http://www.alcyone.de/

Examples

# Beijing
options(longitude = 116.433, latitude = 39.874)

### plot the background of sky chart
data(bright)
data(starcat)

ephem.mercury <- mercury(jd(2010,1,1,length = 365))
track(ephem.mercury, mag = 4, interval.lab = 30, bright.lab = TRUE, 
	starcat = starcat, bright = bright)

ephem.mercury <- mercury(jd(2010,7,30,length = 60))
track(ephem.mercury, mag = 7, interval.lab = 10, cex.star = 2, starcat = starcat, bright = bright)

ephem.venus <- venus(jd(2011,4,30,length = 100))
track(ephem.venus, col.track = "blue", lwd = 3, mag = 5, starcat = starcat, bright = bright)

ephem.mars <- mars(jd(2010,8,30,length = 100))
track(ephem.mars, cex.star = 1.5, grid = FALSE, starcat = starcat, bright = bright)

ephem.jupiter <- jupiter(jd(2010,9,22,length = 100))
track(ephem.jupiter, cex.star = 1.5, col.track = "black" , starcat = starcat, bright = bright)

ephem.saturn <- saturn(jd(2011,9,22,length = 100))
track(ephem.saturn, starcat = starcat, bright = bright)

ephem.uranus <- uranus(jd(2008,8,1,length = 100))
track(ephem.uranus, starcat = starcat, bright = bright)

moonsun documentation built on May 29, 2017, 12:17 p.m.