R: Summary Methods for 'conreg' Objects

conreg-methods {cobs} | R Documentation

## Summary Methods for 'conreg' Objects

### Description

Methods for `conreg` objects

### Usage

    ## S3 method for class 'conreg'
    fitted(object, ...)
    ## S3 method for class 'conreg'
    residuals(object, ...)
    ## S3 method for class 'conreg'
    knots(Fn, ...)

    ## S3 method for class 'conreg'
    lines(x, type = "l", col = 2, lwd = 1.5, show.knots = TRUE,
          add.iSpline = TRUE, force.iSpl = FALSE, ...)

    ## S3 method for class 'conreg'
    plot(x, type = "l", col = 2, lwd = 1.5, show.knots = TRUE,
        add.iSpline = TRUE, force.iSpl = FALSE,
        xlab = "x", ylab = expression(s[c](x)),
        sub = "simple concave regression", col.sub = col, ...)

    ## S3 method for class 'conreg'
    predict(object, x, deriv = 0, ...)

    ## S3 method for class 'conreg'
    print(x, digits = max(3, getOption("digits") - 3), ...)

### Arguments

`object, Fn, x` | an R object of class `conreg`, i.e., typically the result of `conreg(..)`. For `predict()`, `x` is a numeric vector of abscissa values at which to evaluate the concave/convex spline function.
`type, col, lwd, xlab, ylab, sub, col.sub` | plotting arguments as in `plot.default`.
`show.knots` | logical indicating the spline knots should be marked additionally.
`add.iSpline` | logical indicating if an interpolation spline should be considered for plotting. This is only used when it is itself concave/convex, unless `force.iSpl` is `TRUE`.
`force.iSpl` | logical indicating if an interpolating spline is drawn even when it is not convex/concave.
`deriv` | for `predict`, integer specifying the derivate to be computed; currently must be `0` or `1`.
`digits` | number of significant digits for printing.
`...` | further arguments, potentially passed to methods.

### Author(s)

Martin Maechler

### See Also

`conreg`, ....

### Examples

    example(conreg, echo = FALSE)
    class(rc) # "conreg"
    rc # calls the print method
    knots(rc)
    plot(rc)
    ## and now _force_ the not-quite-concave cubic spline :
    plot(rc, force.iSpl=TRUE)

    xx <- seq(-0.1, 1.1, length=201) # slightly extrapolate
    ## Get function s(x)  and first derivative  s'(x) :
    yx <- predict(rc, xx)
    y1 <- predict(rc, xx, deriv = 1)

    op <- par(las=1)
    plot(xx, yx, type = "l",
         main="plot(xx,  predict( conreg(.), xx))")
    par(new=TRUE) # draw the first derivative "on top"
    plot(xx, y1, type = "l", col = "blue",
         axes = FALSE, ann = FALSE)
    abline(h = 0, lty="1A", col="blue")
    axis(4, col="blue", col.axis="blue", col.ticks="blue")
    mtext("first derivative s'(.)", col="blue")
    par(op)

[Package cobs version 1.3-3 Index]