# Calculate grid locations for a spectral GP object.

### Description

This is a version of `expand.grid`

that calculates the grid
locations for a spectral GP object. Gridpoints representing the
part of the domain in which the periodicity of the GP emerges are omitted.

### Usage

1 2 | ```
## S3 method for class 'gp'
expand.gpgrid(object,...)
``` |

### Arguments

`object` |
A GP object, created by |

`...` |
Other arguments. |

### Details

Note that this function is not named `expand.grid.gp`

because
`expand.grid`

is a function, and not an S3 method.

### Value

A matrix of grid locations with the first column the x-dimension and the second the y-dimension, or for one dimensional processes, a vector of grid locations.

### Author(s)

Christopher Paciorek paciorek@alumni.cmu.edu

### References

Type 'citation("spectralGP")' for references.

### See Also

`gp`

, `getgrid.gp`

, `predict.gp`

### Examples

1 2 3 4 5 6 | ```
library(spectralGP)
gp1=gp(128,matern.specdens,c(1,4))
gp2=gp(c(64,64),matern.specdens,c(1,4))
grid1=expand.gpgrid(gp1)
grid2=expand.gpgrid(gp2)
plot(grid2)
``` |