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.</li><li><b><tt>Rs</tt></b> - 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.</li><li><b><tt>Rsh</tt></b> - Shunt resistance in ohms under desired IV curve conditions. May      be a scalar or vector, but vectors must be of same l