# R/locworld.R In GEOmap: Topographic and Geologic Mapping

````locworld` <-
function(shiftlon=0, col="brown", n=2)
{
if(missing(shiftlon)) { shiftlon=0 }
if(missing(col)) { col= "brown" }
if(missing(n)) {  n=2 }

if(n<=0)
{
L = locator(type='p', pch=3, col=col)
}
else
{
L = locator(n, type='p', pch=3, col=col)
}
if(n==2){
rect(L\$x[1], L\$y[1], L\$x[2], L\$y[2], border=col)}

lon = RPMG::fmod(L\$x+shiftlon, 360)
lat = L\$y

utmx = seq(from=(-180), to=180, by=6)
utmy = seq(from =-56, to =72, by=8)

zlon = lon
zlon[zlon>180 & zlon<=359.99] = zlon[zlon>180 & zlon<=359.99]-360

htags =  LETTERS[6:23]
htags = htags[-c(4, 10)]

fzlon = findInterval(zlon[1], utmx)
utmbox = list(x=fzlon, y = htags[findInterval(lat[1], utmy)], lon=utmx[fzlon] ,    lat=utmy[ findInterval(lat[1], utmy) ]   )

fy = findInterval(lat[1], utmy)
utmphi0 = (utmy[fy] +  utmy[fy+1])/2

utmlam0 = (utmx[fzlon] +  utmx[fzlon+1])/2

A = list(lon=lon, lat=L\$y  , LON=RPMG::fmod(lon, 360), LAT=L\$y, utmbox=utmbox , x=L\$x, y=L\$y, UTM0=list(lam=utmlam0, phi=utmphi0), shiftlon=shiftlon)

## print(A)
return(A)
}
```

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