predict.trls {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")

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