R: Bars for interval estimate of the breakpoints

lines.segmented {segmented} | R Documentation

## Bars for interval estimate of the breakpoints

### Description

Draws bars relevant to breakpoint estimates (point estimate and confidence limits) on the current device

### Usage

    ## S3 method for class 'segmented'
    lines(x, term, bottom = TRUE, shift=TRUE, conf.level = 0.95, k = 50,
        pch = 18, rev.sgn = FALSE, ...)

### Arguments

`x` | an object of class `segmented`.
`term` | the segmented variable of the breakpoints being drawn. It may be unspecified when there is a single segmented variable.
`bottom` | logical, indicating if the bars should be plotted at the bottom (`TRUE`) or at the top (`FALSE`).
`shift` | logical, indicating if the bars should be ‘shifted’ on the y-axis before plotting. Useful for multiple breakpoints with overlapped confidence intervals.
`conf.level` | the confidence level of the confidence intervals for the breakpoints.
`k` | a positive integer regulating the vertical position of the drawn bars. See Details.
`pch` | either an integer specifying a symbol or a single character to be used in plotting the point estimates of the breakpoints. See `points`.
`rev.sgn` | should the signs of the breakpoint estimates be changed before plotting? see Details.
`...` | further arguments passed to `segments`, for instance ‘col’ that can be a vector.

### Details

`lines.segmented` simply draws on the current device the point estimates and relevant confidence limits of the estimated breakpoints from a "segmented" object. The y coordinate where the bars are drawn is computed as `usr[3]+h` if `bottom=TRUE` or `usr[4]-h` when `bottom=FALSE`, where `h=(usr[4]-usr[3])/abs(k)` and `usr` are the extremes of the user coordinates of the plotting region. Therefore for larger values of `k` the bars are plotted on the edges. The argument `rev.sgn` allows to change the sign of the breakpoints before plotting. This may be useful when a null-right-slope constraint is set.

### See Also

`plot.segmented` to plot the fitted segmented lines, and `points.segmented` to add the fitted joinpoints.

### Examples

    ## See ?plot.segmented

[Package segmented version 0.5-3.0 Index]