magprojextra: Attractive great circles and thick bands on magproj plots

Description

High level functions to add great circles and thick bands on projections plots. In astronomy these are popular for indicating regions of exclusion surrounding the ecliptic or the Milky-Way plane. Also simple functions to add either the MW bluge to the current projection (magMW) or the sun on a given date (magsun).

Usage

magring(crosseq = 0, peaklat = 0, offset = 0, res = 1000, ...)
magband(crosseq = 0, peaklat = 0, width = 10, res = 1000, ...)
magecliptic(width = 10, ...)
magMWplane(width = 10, ...)
magsun(Ydate = 'get', anti = FALSE, ...)
magMW(...)

Arguments

crosseq

The longitude below the latitude peak of the great circle (or centre of the band) where the centre crosses the equator. See examples to see how this is used in practice.

peaklat

The positive maximum latitude obtained by the great circle (or centre of the band). See examples to see how this is used in practice.

offset

Whether the ring drawn if systematically offset from the great cirlce defined by crosseq and peaklat. Leave at 0 to draw a great circle.

width

How wide whould the band be in degrees. For magecliptic and magMWplane, if this is zero it will draw a line instead.

res

Number of elements making up each side of the band (default should be fine for most plots).

Ydate

The date for the location of the Sun on the spherical grid. Vector in c(M,D) format. If set to 'get' then the function will return the Sun's location for today.

anti

Should the anti-sun position be computed (i.e. the RA and Dec of the position diametrically opposed to the Sun).

…

Arguments passed on to lines (magring), polygon (magband), points (magMW and magsun).

Value

No output. Run for the side effect of producing nice projected plots.

Examples

Run this code

# NOT RUN {
# GAMA fields:
par(mar=c(0.1,0.1,0.1,0.1))
magproj(c(129,141), c(-2,3), type='b', projection='aitoff', centre=c(180,0),
fliplong=TRUE, labloc=c(90,-45), col='red', labeltype = 'sex', crunch=TRUE)
magproj(c(211.5,223.5), c(-2,3), col='red', add=TRUE)
magproj(c(30.2,38.8), c(-10.25,-3.72), col='red', add=TRUE)
magproj(c(30.2,38.8), -6, type='l', add=TRUE, col='grey')
magproj(c(339,351), c(-35,-30), col='red', add=TRUE)

magecliptic(width=10,col=hsv(1/12,alpha=0.3),border=NA)
magecliptic(width=0,col='orange')
# Note this a shortcut for: magring(0,23.4,col='orange')
magMWplane(width=20,col=hsv(v=0,alpha=0.1),border=NA)
magMWplane(width=0,col='darkgrey')
# Note this a shortcut for: magring(76.75,62.6,col='darkgrey')
magMW(pch=16, cex=2, col='darkgrey')
magsun(c(7,26), pch=16, cex=2, col='orange2') #An important date!

magproj(c(174,186), c(-3,2), col='red', add=TRUE)

#Plus SDSS:
magproj(c(110,260), c(-4,70), border='blue', add=TRUE)

magproj(c(35,135,180,217.5,345), c(-3.72,3,2,3,-30)+10, type='t',
plottext=c('G02','G09','G12','G15','G23'), add=TRUE)

legend('topleft', legend=c('GAMA Regions','SDSS Main Survey'), col=c('red','blue'),
pch=c(15,NA), lty=c(NA,1), bty='n')
legend('topright', legend=c('Ecliptic','MW Plane'), col=c(hsv(c(1/12,0), v=c(1,0),
alpha=0.5)), pch=c(15,15), lty=c(1,1), bty='n')
legend('bottomleft', legend=c('Sun', 'MW Centre'), col=c('orange2','darkgrey'), pch=16,
bty='n')
# }

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