% -*- texinfo -*-
% @deftypefn {Function File} {} nper (@var{r}, @var{p}, @var{a}, @var{l}, @var{method})
% Return the number of regular payments of @var{p} necessary to
% amortize @var{a} loan of amount @var{a} and interest @var{r}.
%
% The optional argument @var{l} may be used to specify an additional
% lump-sum payment of @var{l} made at the end of the amortization time.
%
% The optional argument @var{method} may be used to specify whether
% payments are made at the end (@var{'e'}, default) or at the beginning
% (@var{'b'}) of each period.
%
% Note that the rate @var{r} is specified as a fraction (i.e., 0.05,
% not 5 percent).
% @seealso{pv, pmt, rate, npv}
% @end deftypefn