plot.ACF                package:nlme                R Documentation

Plot an ACF Object

Description:

     an 'xyplot' of the autocorrelations versus the lags, with 'type =
     "h"', is produced. If 'alpha > 0', curves representing the
     critical limits for a two-sided test of level 'alpha' for the
     autocorrelations are added to the plot.

Usage:

     ## S3 method for class 'ACF':
     plot(x, alpha, xlab, ylab, grid, ...)

Arguments:

       x: an object inheriting from class 'ACF', consisting of a data
          frame with two columns named 'lag' and 'ACF', representing
          the autocorrelation values and the corresponding lags.  

   alpha: an optional numeric value with the significance level for
          testing if the autocorrelations are zero. Lines corresponding
          to the lower and upper critical values for a test of level
          'alpha' are added to the plot. Default is '0', in which case
          no lines are plotted. 

xlab,ylab: optional character strings with the x- and y-axis labels.
          Default respectively to '"Lag"' and  '"Autocorrelation"'.  

    grid: an optional logical value indicating whether a grid should be
          added to plot. Default is 'FALSE'.

     ...: optional arguments passed to the 'xyplot' function.

Value:

     an 'xyplot' Trellis plot.

Author(s):

     Jose Pinheiro Jose.Pinheiro@pharma.novartis.com and Douglas Bates
     bates@stat.wisc.edu

See Also:

     'ACF', 'xyplot'

Examples:

     fm1 <- lme(follicles ~ sin(2*pi*Time) + cos(2*pi*Time), Ovary)
     plot(ACF(fm1, maxLag = 10), alpha = 0.01)

