rate

% -*- texinfo -*-
% @deftypefn {Function File} {} rate (@var{n}, @var{p}, @var{v}, @var{l}, @var{method})
% Return the rate of return on an investment of present value @var{v} which
% pays @var{p} in @var{n} consecutive periods.
%
% The optional argument @var{l} may be used to specify an additional
% lump-sum payment made at the end of @var{n} periods.
%
% The optional string argument @var{method} may be used to specify
% whether payments are made at the end (@code{'e'}, default) or at the
% beginning (@code{'b'}) of each period.
% @seealso{pv, pmt, nper, npv}
% @end deftypefn