% -*- texinfo -*-
% @deftypefn {Function File} {} npv (@var{r}, @var{p}, @var{i})
% Returns the net present value of a series of irregular (i.e., not
% necessarily identical) payments @var{p} which occur at the ends of @var{n}
% consecutive periods. @var{r} specifies the one-period interest rates and
% can either be a scalar (constant rates) or a vector of the same
% length as @var{p}.
%
% The optional argument @var{i} may be used to specify an initial
% investment.
%
% Note that the rate @var{r} is specified as a fraction (i.e., 0.05,
% not 5 percent).
% @seealso{irr, pv}
% @end deftypefn