variograms {compositions} | R Documentation |

## Variogram functions

### Description

Valid scalar variogram model functions.

### Usage

```
vgram.sph( h , nugget = 0, sill = 1, range= 1,... )
vgram.exp( h , nugget = 0, sill = 1, range= 1,... )
vgram.gauss( h , nugget = 0, sill = 1, range= 1,... )
vgram.cardsin( h , nugget = 0, sill = 1, range= 1,... )
vgram.lin( h , nugget = 0, sill = 1, range= 1,... )
vgram.pow( h , nugget = 0, sill = 1, range= 1,... )
vgram.nugget( h , nugget = 1,...,tol=1E-8 )
```

### Arguments

`h` |
a vector providing distances, a matrix of distance vectors in its rows or a data.frame of distance vectors. |

`nugget` |
The size of the nugget effect (i.e. the limit to 0). At zero itself the value is always 0. |

`sill` |
The sill (i.e. the limit to infinity) |

`range` |
The range parameter. I.e. the distance in which sill is reached or if this does not exist, where the value is in some sense nearly the sill. |

`...` |
not used |

`tol` |
The distance that is considered as nonzero. |

### Details

The univariate variograms are used in the CompLinCoReg as building blocks of multivariate variogram models.

- sph
Spherical variogram

- exp
Exponential variogram

- gauss
The Gaussian variogram.

- gauss
The cardinal sine variogram.

- lin
Linear Variogram. Increases over the sill, which is reached at

`range`

.- pow
The power variogram. Increases over the sill, which is reached at

`range`

.- nugget
The pure nugget effect variogram.

### Value

A vector of size NROW(h), giving the variogram values.

### Author(s)

K.Gerald v.d. Boogaart http://www.stat.boogaart.de

### References

Cressie, N.C. (1993) Spatial statistics

Tolosana, van den Boogaart, Pawlowsky-Glahn (2009) Estimating and modeling variograms of compositional data with occasional missing variables in R, StatGis09

### See Also

`vgram2lrvgram`

,
`CompLinModCoReg`

,
`vgmFit`

### Examples

```
## Not run:
data(juraset)
X <- with(juraset,cbind(X,Y))
comp <- acomp(juraset,c("Cd","Cu","Pb","Co","Cr"))
lrv <- logratioVariogram(comp,X,maxdist=1,nbins=10)
plot(lrv)
## End(Not run)
```

*compositions*version 2.0-8 Index]