Description Usage Arguments Details Value See Also Examples

This erosion algorithm removes counts from hexagon cells at a rate proportional to the cells' exposed surface area. When a cell becomes empty, algorithm removes the emptied cell and notes the removal order. Cell removal increases the exposure of any neighboring cells. The last cell removed is a type of bivariate median.

1 2 | ```
erode(hbin, cdfcut = 0.5)
erode.hexbin(hbin, cdfcut = 0.5)
``` |

`hbin` |
an object of class |

`cdfcut` |
number in (0,1) indicating the confidence level for the limits. |

The algorithm extracts high count cells with containing a given fraction (cdfcut) of the total counts. The algorithm extracts all cells if cdfcut=0. The algorithm performs gray-level erosion on the extracted cells. Each erosion cycle removes counts from cells. The counts removed for each cell are a multiple of the cell's exposed-face count. The algorithm choses the multiple so at least one cell will be empty or have a count deficit on each erosion cycle. The erode vector contain an erosion number for each cell. The value of erode is

6*erosion\_cycle\_ at\_ cell\_ removal - cell\_deficit\_at\_removal

Cells with low values are eroded first. The cell with the highest erosion number is a candidate bivariate median. A few ties in erode are common.

An `"erodebin"`

object (with all the slots from `hbin`

) and
additionally with
high count cells and a component `erode`

that gives the erosion order.

`hexbin`

, `smooth.hexbin`

,
`hcell2xy`

,
`gplot.hexbin`

,
`grid.hexagons`

, `grid.hexlegend`

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 | ```
set.seed(153)
x <- rnorm(10000)
y <- rnorm(10000)
bin <- hexbin(x,y)
smbin <- smooth.hexbin(bin)
erodebin <- erode.hexbin(smbin, cdfcut=.5)
plot(erodebin)
## bivariate boxplot
hboxplot(erodebin, main = "hboxplot(erodebin)")
# show erosion order
plot(bin,style= "lat", minarea=1, maxarea=1,
legend=FALSE, border=gray(.7))
grid.hexagons(erodebin,style= "lat", minarea=1, maxarea=1,pen="green")
xy <- hcell2xy(erodebin)
library("grid")
grid.text(lab = as.character(erodebin@erode), xy$x, xy$y,
gp = gpar(col="white", cex=0.65))
``` |

Embedding an R snippet on your website

Add the following code to your website.

For more information on customizing the embed code, read Embedding Snippets.