# R/GLOBE.ORTH.R In GEOmap: Topographic and Geologic Mapping

#### Documented in GLOBE.ORTH

```GLOBE.ORTH<-function(lam0, phi1, R=1, plotmap=TRUE, plotline=TRUE, add=FALSE,
map='coastmap', mapcol =grey(.2) , linecol = grey(.7), fill=FALSE )
{
###   use orthogonal projection to plot a global view
if(missing(R)) R = 1
if(missing( plotmap))  plotmap=TRUE
if(missing( plotline))  plotline=TRUE

if(missing(map))
{
plotmap = FALSE

}

if(missing( mapcol)) mapcol =grey(.2)
if(missing(linecol )) linecol = grey(.7)

Marids =  list()
Parals =  list()

lats = seq(from=90, to=-90, by=-2)
lons = seq(from=0, to=340, by=20)

for(i in 1:length(lons) )
{
Marids[[i]] = ortho.proj(lats, lons[i], lam0, phi1, R)
}

lats = seq(from=90, to=-90, by=-10)
lons = seq(from=lam0-180, to=lam0+180, by=2)
for(i in 1:length(lats) )
{
Parals[[i]] = ortho.proj(lats[i], lons , lam0, phi1, R)
}

ATOL= 0.4

{
plot(c(-R, R), c(-R,R), asp=1, type='n', ann=FALSE, axes=FALSE)
}

###   mapcol =rgb(1, .7, .7)
if(plotmap)
{

for(i in 1:length(map\$STROKES\$num))
{

j1 = map\$STROKES\$index[i] + 1
j2 = j1 + map\$STROKES\$num[i] - 1
LONS = map\$POINTS\$lon[j1:j2]
LATS = map\$POINTS\$lat[j1:j2]

XY = ortho.proj(LATS, LONS , lam0, phi1, R)

x  = XY\$x[XY\$cosc>=0]
y = XY\$y[XY\$cosc>=0]

n = length(x)

if(n<=2) next

dis = sqrt(  (x[1:(n-1)]-x[2:(n)])^2 + (y[1:(n-1)]-y[2:(n)])^2 )

if(any(dis>ATOL))
{

w = which(dis>ATOL)
x = insertNA(x, w )
y = insertNA(y, w )
##  lines(nx, ny , col='green' )
}
lines(x, y , col=mapcol )
if(fill==TRUE)
{
polygon(x,y,col=mapcol )

}
}
}

if(plotline)
{

circ = darc( rad=1, ang1=0, ang2=360, x1=0, y1=0, n=1)
lines(circ)

for(i in 1:length(Marids))
{
x = Marids[[i]]\$x
y = Marids[[i]]\$y
flag = Marids[[i]]\$cosc>=0

lines(x[flag],y[flag], col=linecol)

}

for(i in 1:length(Parals))
{
x = Parals[[i]]\$x
y = Parals[[i]]\$y
flag = Parals[[i]]\$cosc>=0
lines(x[flag],y[flag], col=linecol)
# points(x[flag],y[flag], col='red')

# locator()

}

}

}
```

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GEOmap documentation built on Jan. 20, 2018, 9:27 a.m.