R: Add a Legend to a Hexbin Plot

grid.hexlegend {hexbin} | R Documentation

## Add a Legend to a Hexbin Plot

### Description

Plots the legend for the `plot` method of `hexbin`. Provides a legend indicating the count representations.

### Usage

    grid.hexlegend(legend, ysize, lcex, inner, style = ,
      	   minarea = 0.05, maxarea = 0.8, mincnt = 1, maxcnt, trans = NULL,
    	   inv = NULL, colorcut, density = NULL, border = NULL, pen = NULL,
    	   colramp = function(n) { LinGray(n,beg = 90,end = 15) },
               leg.unit = "native")

### Arguments

`legend` | positive number giving width of the legend in inches.
`ysize` | height of legend in inches
`lcex` | the characters expansion size for the text in the legend, see `par(cex=)`.
`inner` | the inner diameter of a hexagon in inches.
`style` | the hexagon style; see `grid.hexagons`.
`minarea, maxarea` | fraction of the cell area for the lowest and largest count, respectively.
`mincnt, maxcnt` | minimum and maximum count accepted in `plot`.
`trans` | a transformation function for the counts such as `sqrt`.
`inv` | the inverse transformation function.
`colorcut` | numeric vector of values covering [0, 1] the determine hexagon color classes boundaries and hexagon legend size boundaries.
`border` | argument for `polygon()`. Draw the border for each hexagon.
`density` | argument for `polygon()` filling. A `0` causes the polygon not to be filled.
`pen` | color argument used for `polygon(col = .)`. Determines the color with which the polygon will be filled.
`colramp` | function accepting an integer `n` as an argument and returning n colors.
`leg.unit` | unit to use

### Details

The `plot` method for `hexbin` objects calls this function to produce a legend by setting the graphics parameters, so `hex.legend` itself is not a standalone function.

The legend function is preliminary. Later version will include refinements and handle extreme cases (small and large) for cell size and counts.

See the Details section of `grid.hexagons`'s help page.

### Value

This function does not return any value.

### Author(s)

Dan Carr <dcarr@voxel.galaxy.gmu.edu>

ported by Nicholas Lewin-Koh <kohnicho@comp.nus.edu.sg>

### References

see in `grid.hexagons`.

### See Also

`hexbin`, `grid.hexagons`, `smooth.hexbin`, `erode.hexbin`, `hcell2xy`, `gplot.hexbin`,

### Examples

    ## Not a stand alone function; typically only called from plot.hexbin()

    ## Not run:
      grid.hexlegend(legend = 2, ysize = 1,lcex=8,inner=0.2,
                     maxcnt = 100, colorcut = c(0.5,0.5))

    ## End(Not run)

[Package hexbin version 1.28.1 Index]