map2lonlat {oce} | R Documentation |
Convert from x-y coordinates to longitude and latitude. This is normally called internally within oce; see ‘Bugs’.
map2lonlat(x, y, init = c(0, 0))
x |
vector containing the x component of points in the projected space, or
a list containing items named |
y |
vector containing the y coordinate of points in the projected space
(ignored if |
init |
vector containing the initial guesses for longitude and latitude, presently ignored. |
A projection must already have been set up, by a call to mapPlot
or lonlat2map
. It should be noted that not all projections are
handled well; see ‘Bugs’.
A list containing longitude
and latitude
, with NA
values indicating points that are off the globe as displayed.
oce
uses project in the rgdal
package to handle projections. Only those projections that have inverses are
permitted within oce
, and even those can sometimes yield errors, owing
to limitations in rgdal.
Dan Kelley
lonlat2map
does the inverse operation.
A map must first have been created with mapPlot
.
Other functions related to maps: lonlat2map
,
lonlat2utm
, mapArrows
,
mapAxis
, mapContour
,
mapDirectionField
, mapGrid
,
mapImage
, mapLines
,
mapLocator
,
mapLongitudeLatitudeXY
,
mapPlot
, mapPoints
,
mapPolygon
, mapScalebar
,
mapText
, mapTissot
,
oceCRS
, shiftLongitude
,
utm2lonlat
## Not run: library(oce) ## Cape Split, in the Minas Basin of the Bay of Fundy cs <- list(longitude=-64.49657, latitude=45.33462) xy <- lonlat2map(cs, projection="+proj=merc") map2lonlat(xy) ## End(Not run)