R: Space-time kernel

kernel3d {splancs} | R Documentation

## Space-time kernel

### Description

Compute the space-time kernel

### Usage

    kernel3d(pts, times, xgr, ygr, zgr, hxy, hz)

### Arguments

`pts` | A matrix of event coodinates x,y.
`times` | A vector of event times, t.
`xgr` | The values of x at which to compute the kernel function.
`ygr` | The values of y at which to compute the kernel function.
`zgr` | The values of time at which to compute the kernel function.
`hxy` | The quartic kernel width in the x and y direction.
`hz` | The quartic kernel width in the temporal direction.

### Value

A list is returned. Most of the components are just copies of the input parameters, except for the `$v` parameter. This is a three dimensional array containing the kernel-smoothed values. Its dimension is `[length(xgr),length(ygr),length(tgr)]`.

### References

Rowlingson, B. and Diggle, P. 1993 Splancs: spatial point pattern analysis code in S-Plus. Computers and Geosciences, 19, 627-655; the original sources can be accessed at: https://www.maths.lancs.ac.uk/~rowlings/Splancs/. See also Bivand, R. and Gebhardt, A. 2000 Implementing functions for spatial statistical analysis using the R language. Journal of Geographical Systems, 2, 307-317.

### See Also

`kerview`

### Examples

    data(burkitt)
    b3d <- kernel3d(burpts, burkitt$t, seq(250,350,10), seq(250, 400, 10),
      seq(365,5800,365), 30, 200)
    brks <- quantile(b3d$v, seq(0,1,0.05))
    cols <- heat.colors(length(brks)-1)
    oldpar <- par(mfrow=c(3,5))
    for (i in 1:15) image(seq(250,350,10), seq(250, 400, 10), b3d$v[,,i],
      asp=1, xlab="", ylab="", main=1960+i, breaks=brks, col=cols)
    par(oldpar)

[Package splancs version 2.01-43 Index]