# hexbin

##### Bivariate Binning into Hexagon Cells

Creates a `"hexbin"`

object. Basic components are a cell id and
a count of points falling in each occupied cell.

Basic methods are `show()`

, `plot()`

and `summary()`

, but also `erode`

.

- Keywords
- dplot

##### Usage

```
hexbin(x, y, xbins = 30, shape = 1,
xbnds = range(x), ybnds = range(y),
xlab = NULL, ylab = NULL, IDs = FALSE)
```

##### Arguments

- x, y
vectors giving the coordinates of the bivariate data points to be binned. Alternatively a single plotting structure can be specified: see

`xy.coords`

.`NA`

's are allowed and silently omitted.- xbins
the number of bins partitioning the range of xbnds.

- shape
the

*shape*= yheight/xwidth of the plotting regions.- xbnds, ybnds
horizontal and vertical limits of the binning region in x or y units respectively; must be numeric vector of length 2.

- xlab, ylab
optional character strings used as labels for

`x`

and`y`

. If`NULL`

, sensible defaults are used.- IDs
logical indicating if the individual cell “IDs” should be returned, see also below.

##### Details

Returns counts for non-empty cells only. The plot shape must be maintained for hexagons to appear with equal sides. Some calculations are in single precision.

Note that when plotting a `hexbin`

object, the
grid package is used.
You must use its graphics (or those from package lattice if you
know how) to add to such plots.

##### Value

an S4 object of class `"hexbin"`

.
It has the following slots:

vector of cell ids that can be mapped into the (x,y) bin centers in data units.

vector of counts in the cells.

The x center of mass (average of x values) for the cell.

The y center of mass (average of y values) for the cell.

number of hexagons across the x axis. hexagon inner diameter =diff(xbnds)/xbins in x units

plot shape which is yheight(inches) / xwidth(inches)

x coordinate bounds for binning and plotting

y coordinate bounds for binning and plotting

The i and j limits of cnt treated as a matrix cnt[i,j]

number of (non NA) (x,y) points, i.e., `sum(* @count)`

.

number of cells, i.e., `length(* @count)`

, etc

the function call.

character strings to be used as axis labels.

of class, `"integer or NULL"`

, only if `IDs`

was true, an integer vector of length `n`

where
`cID[i]`

is the cell number of the i-th original point
`(x[i], y[i])`

. Consequently, the `cell`

and `count`

slots are the same as the `names`

and entries of
`table(cID)`

, see the example.

##### References

Carr, D. B. et al. (1987)
Scatterplot Matrix Techniques for Large \(N\).
*JASA* **83**, 398, 424--436.

##### See Also

##### Examples

`library(hexbin)`

```
# NOT RUN {
set.seed(101)
x <- rnorm(10000)
y <- rnorm(10000)
(bin <- hexbin(x, y))
## or
plot(hexbin(x, y + x*(x+1)/4),
main = "(X, X(X+1)/4 + Y) where X,Y ~ rnorm(10000)")
## Using plot method for hexbin objects:
plot(bin, style = "nested.lattice")
hbi <- hexbin(y ~ x, xbins = 80, IDs= TRUE)
str(hbi)
tI <- table(hbi@cID)
stopifnot(names(tI) == hbi@cell,
tI == hbi@count)
## NA's now work too:
x[runif(6, 0, length(x))] <- NA
y[runif(7, 0, length(y))] <- NA
hbN <- hexbin(x,y)
summary(hbN)
# }
```

*Documentation reproduced from package hexbin, version 1.27.1, License: GPL-2*