# amacrine: Hughes' Amacrine Cell Data

## Description

Austin Hughes' data: a point pattern
of displaced amacrine cells in the retina of a rabbit.
A marked point pattern.## format

An object of class `"ppp"`

representing the point pattern of cell locations.
Entries include
ll{
`x`

Cartesian $x$-coordinate of cell
`y`

Cartesian $y$-coordinate of cell
`marks`

factor with levels `off`

and `on`

indicating ``off'' and ``on'' cells
}
See `ppp.object`

for details of the format.## source

Peter Diggle, personal communication## Notes

Austin Hughes' data: a point pattern
of displaced amacrine cells in the retina of a rabbit.
152 ``on'' cells and 142 ``off'' cells in a rectangular sampling frame.The true dimensions of the rectangle are 1060 by 662 microns.
The coordinates here are scaled to a rectangle of height 1 and width
$1060/662 = 1.601$ so the unit of measurement is approximately 662 microns.

The data were analysed by Diggle (1986).

## References

Diggle, P. J. (1986).
Displaced amacrine cells in the retina of a
rabbit: analysis of a bivariate spatial point pattern.
*J. Neurosci. Meth.* **18**, 115--125.