geoidentify: Identifies points on plots using lat and lon coordinates.
In geo: Draw and Annotate Maps, Especially Charts of the North Atlantic

Description Usage Arguments Details Value Side Effects See Also Examples

Works the same way as identify except that it also accepts coordinates as lat and lon. Identifies points on a plot identified by the user.

1 2	geoidentify(lat, lon = NULL, labels = 1, n = 0, plot = TRUE, atpen = TRUE, offset = 0.5, col = 1, cex = 1)

`lat,lon`	Coordinates of points. The coordinates can be given by two vectors or a data.frame containin vectors `lat` and `lon`.
`labels`	Vector giving labels for each of the points. If supplied, this must have the same length as lat and lon. As a default the vector indece number of the points will be used.
`n`	Maximum number of points to be identified.
`plot`	If true, geoidentify plots the labels if the points identified.
`atpen`	If true, plotted identification is relative to locator position when the point is identified; otherwise, plotting is relative to the identified lat,lon value. This can be useful when points are crowded. Default is true.
`offset`	Identification is plotted as a text string, moved offset charecter from the point. If the locator was left (right) of the nearest point, the label will be offset to the left (right) of the point.
`col`	The color of the labels.
`cex`	Character size expansion of label characters.

Observations that have missing values in either lat or lon are treated as if they were not given. When using the X11 driver under the X Window System, a point is identified by positioning the cursor over the point and pressing the left button. To exit identify press the middle button (both buttons on a two button mouse) while the cursor is in the graphics window. The same procedure is used under the suntools driver. This function may also be used with the "tek" drivers.

Some devices that do not allow interaction prompt you for an x,y pair. The nearest point to the locator position is identified, but must be at most 0.5 inches away. In case of ties, the earliest point is identified.

Indeces (in lat and lon) corresponding to the identified points.

Labels are placed on the current plot if plot is true.

identify, geolocator, geotext.

## Not run:        geoidentify(stations, labels = stations$temp)
       # plots the temperature in the closest measuring point.

       geoidentify(stations, atpen = FALSE) 
       # plots the indece number of the station closest to
       # where pointed at the stations position.

## End(Not run)