hexbin {hexbin} | R Documentation |
Creates a "hexbin"
object. Basic components are a cell id and
a count of points falling in each occupied cell.
Basic methods are plot()
(plot.hexbin) and
summary()
(summary.hexbin), but also the functions
smooth.hexbin
and erode.hexbin
.
hexbin(x, y, xbins=30, shape=1, xbnds=range(x), ybnds=range(y), IDs = FALSE)
x |
a vector of numbers. The first coordinate of bivariate data to be binned. |
y |
a vector of numbers. The second coordinate of bivariate data to be binned. |
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. |
IDs |
logical indicating if the individual cell “IDs” should be returned, see also below. |
Returns counts for non-empty cells. The plot shape must be maintained for hexagons to appear with equal sides. Some calculations are in single precision.
Note that when plotting with plot.hexbin
, the plotting
parameters are changed during the plot and it returns the changed
par
parameters, so to utilize the same plot window one
must be sure to also use these par
values for it to work
properly (see the use of screenpar
in the examples below).
an object of class "hexbin"
.
The list structure typically contains the following components:
cell |
vector of cell ids that can be mapped into the (x,y) bin centers in data units. |
cnt |
vector of counts in the cells. |
xcm |
The x center of mass (average of x values) for the cell. |
ycm |
The y center of mass (average of y values) for the cell. |
xbins |
number of hexagons across the x axis. hexagon inner diameter =diff(xbnds)/xbins in x units |
xbnds |
x coordinate bounds for binning and plotting |
ybnds |
y coordinate bounds for binning and plotting |
shape |
plot shape which is yheight(inches) / xwidth(inches) |
dim |
The i and j limits of cnt treated as a matrix cnt[i,j] |
cell.id |
only if IDs was true, an integer vector of length
n where cell.id[i] is the cell number of the i-th
original point (x[i], y[i]) . |
Carr, D. B. et al. (1987) Scatterplot Matrix Techniques for Large N. JASA 83, 398, 424–436.
hcell2xy
, hcell
,
plot.hexbin
, hboxplot
,
hdiffplot
, hmatplot
,
hexagons
, hex.legend
.
x <- rnorm(10000) y <- rnorm(10000) bin <- hexbin(x,y) ## Using plot method for hexbin objects: plot(bin, style = "nested.lattice") ## lower resolution binning and overplotting with counts bin <- hexbin(x,y,xbins=25) screenpar <- plot.hexbin(bin, style="lattice", minarea=1, maxarea=1, density=0, border=TRUE) oldpar <- par(screenpar) # reset graphics to the plot on the screen xy <- hcell2xy(bin) text(xy$x,xy$y,as.character(bin$cnt),adj=.5,cex=.3) points(x,y) # to show points rather than counts par(oldpar) #reset graphics ## Use (and 'check') IDs: bin3 <- hexbin(x, y, IDs = TRUE) tb <- table(bin3$cell.id) stopifnot(bin3$cnt == c(tb), bin3$cell == rownames(tb))