spatstat (version 1.52-1)

mucosa: Cells in Gastric Mucosa

Description

A bivariate inhomogeneous point pattern, giving the locations of the centres of two types of cells in a cross-section of the gastric mucosa of a rat.

Usage

data(mucosa)

Format

An object of class "ppp", see ppp.object. This is a multitype point pattern with two types of points, ECL and other.

Details

This point pattern dataset gives the locations of cell centres in a cross-section of the gastric mucosa (mucous membrane of the stomach) of a rat. The rectangular observation window has been scaled to unit width. The lower edge of the window is closest to the outside of the stomach.

The cells are classified into two types: ECL cells (enterochromaffin-like cells) and other cells. There are 86 ECL cells and 807 other cells in the dataset. ECL cells are a type of neuroendocrine cell which synthesize and secrete histamine. One hypothesis of interest is whether the spatially-varying intensities of ECL cells and other cells are proportional.

The data were originally collected by Dr Thomas Berntsen. The data were discussed and analysed in Moller and Waagepetersen (2004, pp. 2, 169).

The associated object mucosa.subwin is the smaller window to which the data were restricted for analysis by Moller and Waagepetersen.

References

Moller, J. and Waagepetersen, R. (2004). Statistical Inference and Simulation for Spatial Point Processes. Chapman and Hall/CRC.

Examples

# NOT RUN {
  plot(mucosa, chars=c(1,3), cols=c("red", "green"))
  plot(mucosa.subwin, add=TRUE, lty=3)
# }