image.count: Creates image for a 2-d histogram from irregular locations
Description
Discretizes a matrix of 2-d locations and counts the
number of
occurrences for each grid box.
Usage
image.count(x, grid=NULL, nrow=64, ncol=64)
Arguments
x
grid
A list with components x and y of equally spaced values describing the
centers of the grid points. The default is to use nrow and ncol and the
ranges of the data locations (x) to construct a grid.
nrow
Number of rows for the image. Note that nrows equals the number of x
values and corresponds to the horizontal dimension.
ncol
Number of columns for the image. Note that
ncol= number of y values and will
be the vertical dimension.
Value
An list in image format. Components x and y are the grid values , z is a
nrow X ncol matrix
with the Z values. NA's are placed at cell locations where Z data has
not been supplied.