fields (version 6.6.2)

world: Plot of the world

Description

Plots quickly, medium resolution outlines of large land masses and bodies of water.

Usage

world(ylim = c(-90, 90), xlim = NULL, add = FALSE, asp = 1,
                 xlab = "", ylab = "", xaxt = "n", yaxt = "n", eps =
                 0.1, col=1,shift = FALSE, 
                 fill=FALSE, col.water="white", col.land="darkgrey",alpha=NA, ...)
world.land( col.water = "white", col.land = "darkgrey",alpha=NA, ...)
world.color(obj,xlim= c(-180,180), ylim=c(-90,90), 
             col.water="white",col.land="darkgrey", ... )
in.land.grid( grid.list)

Details

Both functions use the FIELDS dataset world.dat for the coordinates. See the longstanding maps package for similar functionality The main advantage of these functions is that they are fast and easy to modify. The shift option to center over the dateline is useful because often plots of oceanic and atmospheric information center the map this way.

The function world.color can be used separately but is also called by world with fill being TRUE. When used alone it will just add the colored landmasses and water to an existing plot. It is easy to modify just to add the land masses and use the existing back ground color as water. Unfortunately world.color will not work when shift is TRUE. Use the maps package to accomplish this. Howevr, the current code could be modified if you need this option. Thanks to Steve McIntyre for suggesting and testing the fill option.

The function world.land adds to an existing plot a polygon fill of the land masses the water in this case is just the lakes not the ocean. Used with transparency this provides a clearer reference than just outlines.

in.land.grid Takes the grid information in the form of a grid list and returns a logical image matrix. TRUE means that the grid point is not in an ocean or a lake. For very large grids (500X1000) this make take a minute or so.

See Also

US, in.poly, in.poly.grid

Examples

world()
# add the US
US( add=TRUE,col="blue")


world( fill=TRUE) # land filled in dark grey 


## Western Europe (*which* big islands are missing?)
## with a coordinate grid:

world(xlim=c(-10,18),ylim=c(36,60), 
    xaxt = "s", yaxt = "s", fill=TRUE, col.land="darkgreen")

box() # add back in the box that was obscured by the ocean fill.

# add back in outline of land.
world( add=TRUE,lwd=1.5, col="green")

grid()

grid.list<- list( x= seq(-160,-60,,200), y= seq( 25, 55,,100))
look<- in.land.grid( grid.list)

world()
# mask for land in grid
image( grid.list$x, grid.list$y, look, add=TRUE)