One-period percentage change, annualized (in decimal fraction).
Syntax: @pcha(x)
x: series
n: integer, series
Return: series
Returns one-period percentage change (in decimal fraction) in the series x:
This function is panel aware.
Examples
If x is a series of monthly profits, then
show @pcha(x)
produces a linked series of annualized profit growth in decimal fraction.
Cross-references
See also
@pc,
@pca,
@pch,
@pchy, and
@pcy.
is the lag associated with the yearly frequency (e.g., 
for quarterly data, 
for monthly data).