corClasses: Correlation Structure Classes
Description
Standard classes of correlation structures (corStruct)
  available in the nlme package.Value
- Available standard classes:
- corAR1autoregressive process of order 1.
- corARMAautoregressive moving average process, with arbitrary
    orders for the autoregressive and moving average components.
- corCAR1continuous autoregressive process (AR(1) process for a
    continuous time covariate).
- corCompSymmcompound symmetry structure corresponding to a
    constant correlation.
- corExpexponential spatial correlation.
- corGausGaussian spatial correlation.
- corLinlinear spatial correlation.
- corRatioRational quadratics spatial correlation.
- corSpherspherical spatial correlation.
- corSymmgeneral correlation matrix, with no additional
    structure.
References
Pinheiro, J.C., and Bates, D.M. (2000) "Mixed-Effects Models
  in S and S-PLUS", Springer.See Also
corAR1, corARMA,
  corCAR1, corCompSymm,
  corExp, corGaus,
  corLin,
  corRatio, corSpher,
  corSymm,
  summary.corStruct