GEOmap (version 2.5-11)

GLOBE.ORTH: Plot globe with orthogonal

Description

Plot globe with orthogonal

Usage

GLOBE.ORTH(lam0, phi1, R = 1, plotmap = TRUE, plotline=TRUE, add=FALSE,
 map = coastmap, mapcol = grey(0.2), linecol = grey(0.7), fill=FALSE)

Value

Graphical Side effects

Arguments

lam0

view origin longitude, degrees

phi1

view origin latitude, degrees

R

Radius of sphere, default=1

plotmap

logical, default=TRUE, add map

plotline

logical, default=TRUE, add grid of lat-lons

add

logical, default=FALSE, Do not start a new plot, rather add to existing plot

map

GEOmap list

mapcol

color for map

linecol

color for meridians and parallels

fill

fill polygons with color, default=FALSE

Author

Jonathan M. Lees<[e-mail]>

Details

Plots whole globe with grid.

References

Snyder, John P., Map Projections- a working manual, USGS, Professional Paper, 1987.

See Also

setPROJ, projtype, plotGEOmap

Examples

######  simple map of world viewed at 40 degrees latitude
R = 1
R.MAPK = 6378.2064

phi1=40

viewlam = seq(from=0, to=340, by=2)

data(coastmap)

K=1
GLOBE.ORTH(viewlam[K], phi1, R=1, plotmap=TRUE)
######


OLIM = c(20, 40, 10, 40)
TLIM = c(-20, -10, -30, -10)


 olat = runif(1, OLIM[1], OLIM[2])
         olon = runif(1, OLIM[3], OLIM[4] )

          tlat = runif(1,TLIM[1], TLIM[2] )
         tlon = runif(1, TLIM[3], TLIM[4])

GLOBE.ORTH(olon, olat, 1,plotmap=FALSE )

 XYorg = ortho.proj(olat, olon, olon, olat, 1)
 XYtarg = ortho.proj(tlat, tlon, olon, olat, 1)

points( XYorg , col='red')
points(XYtarg , col='blue')
 da = distaz(olat, olon, tlat, tlon)
 ed2 =  Ellipsoidal.Distance(olat, olon, tlat, tlon, a=R.MAPK*1000, b=R.MAPK*1000)

  A = along.great(olat*pi/180, olon*pi/180,
seq(from=0, to=da$del, by=2)*pi/180,  da$az*pi/180)

     lat=A$phi*180/pi
     lon = A$lam*180/pi

 XYalong = ortho.proj(lat, lon, olon, olat, 1)

lines(XYalong , col='purple')

M = merid(tlon, lat1=tlat, phi1=olat, lam0=olon, R=1, by=2)

lines(M$x, M$y, col='blue' )

M2 = merid(olon, lat1=olat,  phi1=olat, lam0=olon,R=1, by=2)

lines(M2$x, M2$y, col='red' )

 leg = c( paste("del=", round(da$del)), paste("DA=", round(da$az),
 round(da$baz) ),
 paste("ED=", round(ed2$az) ,  round(ed2$revaz) ))
 
legend("topleft", legend=leg)