predict.trls             package:spatial             R Documentation

Predict method for trend surface fits

Description:

     Predicted values based on trend surface model object

Usage:

     ## S3 method for class 'trls':
     predict(object, x, y, ...)

Arguments:

  object: Fitted trend surface model object returned by 'surf.ls' 

       x: Vector of prediction location eastings (x coordinates) 

       y: Vector of prediction location northings (y coordinates) 

     ...: further arguments passed to or from other methods. 

Value:

     'predict.trls' produces a vector of predictions corresponding to
     the prediction locations. To display the output with 'image' or
     'contour', use 'trmat' or convert the returned vector to matrix
     form.

References:

     Venables, W. N. and Ripley, B. D. (2002) _Modern Applied
     Statistics with S._ Fourth edition.  Springer.

See Also:

     'surf.ls', 'trmat'

Examples:

     data(topo, package="MASS")
     topo2 <- surf.ls(2, topo)
     topo4 <- surf.ls(4, topo)
     x <- c(1.78, 2.21)
     y <- c(6.15, 6.15)
     z2 <- predict(topo2, x, y)
     z4 <- predict(topo4, x, y)
     cat("2nd order predictions:", z2, "\n4th order predictions:", z4, "\n")

