POSY c1,p1 c2,p2 ...
POSY c1,p1 c2,p2 ... args
Defines a transfer function by a one dimensional ``posynomial'', like a polynomial, except that the powers are arbitrary, and usually non-integer.
There is no corresponding capability in any SPICE that I know of.
For capacitors, this function defines charge as a function of voltage. For inductors, it defines flux as a function of current.
For fixed sources, it defines voltage or current as a function of time.
Normal use of this function required positive input (voltage or current). The result is zero if the input is negative. Raising a negative number to a non-integer power would produce a complex result, which implies a non-causal result, which cannot be represented in a traditional transient analysis.
The transfer function is defined by:
if (in > 0){ out = (c1*in^p1) + (c2*in^p2) + .... }else{ out = 0. }