# boundary.Fstats: Boundary for F Statistics In strucchangeRcpp: Testing, Monitoring, and Dating Structural Changes: C++ Version

## Description

Computes boundary for an object of class `"Fstats"`

## Usage

 ```1 2 3``` ```## S3 method for class 'Fstats' boundary(x, alpha = 0.05, pval = FALSE, aveF = FALSE, asymptotic = FALSE, ...) ```

## Arguments

 `x` an object of class `"Fstats"`. `alpha` numeric from interval (0,1) indicating the confidence level for which the boundary of the supF test will be computed. `pval` logical. If set to `TRUE` a boundary for the corresponding p values will be computed. `aveF` logical. If set to `TRUE` the boundary of the aveF (instead of the supF) test will be computed. The resulting boundary then is a boundary for the mean of the F statistics rather than for the F statistics themselves. `asymptotic` logical. If set to `TRUE` the asymptotic (chi-square) distribution instead of the exact (F) distribution will be used to compute the p values (only if `pval` is `TRUE`). `...` currently not used.

## Value

an object of class `"ts"` with the same time properties as the time series in `x`

`Fstats`, `plot.Fstats`
 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14``` ```## Load dataset "nhtemp" with average yearly temperatures in New Haven data("nhtemp") ## plot the data plot(nhtemp) ## test the model null hypothesis that the average temperature remains ## constant over the years for potential break points between 1941 ## (corresponds to from = 0.5) and 1962 (corresponds to to = 0.85) ## compute F statistics fs <- Fstats(nhtemp ~ 1, from = 0.5, to = 0.85) ## plot the p values without boundary plot(fs, pval = TRUE, alpha = 0.01) ## add the boundary in another colour lines(boundary(fs, pval = TRUE, alpha = 0.01), col = 2) ```