exemple script iapws97

voila un exemple de la fonction dans script iapws97 ( que l'on peut pas importer par la formulation simple import iapws97 * , ca marche pas ?) l'aPPLI IAPWS comprend un folder fait de plusieurs scripts donc un "cache " ......
voila extrait du script iapws97 con,tenat des fonctiosn non applables de facon simple ..

def _PSat_T(T):
 """Define the saturated line, P=f(T)
 """
 # Check input parameters
 if T < 273.15 or T > Tc:
 raise NotImplementedError("Incoming out of bound")
 n = [0, 0.11670521452767E+04, -0.72421316703206E+06, -0.17073846940092E+02,
 0.12020824702470E+05, -0.32325550322333E+07, 0.14915108613530E+02,
 -0.48232657361591E+04, 0.40511340542057E+06, -0.23855557567849E+00,
 0.65017534844798E+03]
 tita = T+n[9]/(T-n[10])
 A = tita**2+n[1]*tita+n[2]
 B = n[3]*tita**2+n[4]*tita+n[5]
 C = n[6]*tita**2+n[7]*tita+n[8]
 return (2*C/(-B+(B**2-4*A*C)**0.5))**4
def _TSat_P(P):
 """Define the saturated line, T=f(P)
 """
 # Check input parameters
 if P < 611.212677/1e6 or P > 22.064:
 raise NotImplementedError("Incoming out of bound")
 n = [0, 0.11670521452767E+04, -0.72421316703206E+06, -0.17073846940092E+02,
 0.12020824702470E+05, -0.32325550322333E+07, 0.14915108613530E+02,
 -0.48232657361591E+04, 0.40511340542057E+06, -0.23855557567849E+00,
 0.65017534844798E+03]
 beta = P**0.25
 E = beta**2+n[3]*beta+n[6]
 F = n[1]*beta**2+n[4]*beta+n[7]
 G = n[2]*beta**2+n[5]*beta+n[8]
 D = 2*G/(-F-(F**2-4*E*G)**0.5)
 return (n[10]+D-((n[10]+D)**2-4*(n[9]+n[10]*D))**0.5)/2