st be of
%      same length as all other input vectors.
% * *|I0|* - Diode saturation current in amperes under desired IV curve
%      conditions. May be a scalar or vector, but vectors must be of same
%      length as all other input vectors.
% * *|Rs|* - Series resistance in ohms under desired IV curve conditions. May
%      be a scalar or vector, but vectors must be of same length as all
%      other input vectors.
% * *|Rsh|* - Shunt resistance in ohms under desired IV curve conditions. May
%  