spatstat.data (version 3.0-1)

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.

Usage

data(amacrine)

Format

An object of class "ppp" representing the point pattern of cell locations. Entries include

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.

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.

Examples

  if(require(spatstat.geom)) {
amacrine
(Ama <- rescale(amacrine))
  }