find.elem-methods: Checks if the points (xy$x, xy$y) are in the 'fvcom.grid'...
In ocean: Biophysical Oceanography Tools

Description Arguments Value Examples

Given a grid and a point or set of points, find.elem returns the element number of each point in the grid. NA is returned for any point that does not lie within the grid. x and y must be the same length.

`grid`	A `fvcom.grid` instance.
`xy`	A `data.frame` with components `x` and `y` with the x and y locations of the points.
`units`	Either 'll' for latitude and longitude or 'm' for meters.

A vector of integer values of length nrow(xy). The values are indexes into the elements of grid.

{
# Create a regular matrix grid
nodes = get.nodes(ocean.demo.grid)
lattice.grid = expand.grid(x=seq(min(nodes$x), max(nodes$x), len=50),
                           y=seq(min(nodes$y), max(nodes$y), len=50))
elems = find.elem(ocean.demo.grid, lattice.grid, units="m")
# Plot the result
plot(lattice.grid$x, lattice.grid$y, pch=15,
     col=jet.colors(max(elems, na.rm=TRUE) + 2)[elems+2])
}