Display a correlogram - ---------------------
^acplot^ varname [^, l^ags^(^#^)^ ^se^ ^pr^int ^sp^ike graph_options ]
Description - -----------
^acplot^ graphs the first ^lags()^ autocorrelations.
Options - -------
^lags(^#^)^ specifies the number of lags. If not specified, the first 20 autocorrelations are graphed.
^se^ adds standard-error bands to the graph.
^print^ prints out the autocorrelations. If ^se^ is requested, the standard errors are also printed.
^spike^ causes the autocorrelations to be shown as a series of spikes drawn vertically from zero.
graph_options refers to any of the options of ^graph, twoway^.
Examples - --------
. ^acplot durtemp^ . ^acplot durtemp, sp^ . ^acplot durtemp, se pr^
Methods and formulas - --------------------
The standard error of the autocorrelations is estimated by Bartlett's approximation.
Author - ------
Nicholas J. Cox, University of Durham, after Sean Becketti's ac. n.j.cox@@durham.ac.uk