vectorize wetsnow

smrt/permittivity/wetsnow.py

@@ -1,5 +1,6 @@
 # coding: utf-8
 
+import numpy as np
 from ..core.layer import layer_properties
 from .ice import ice_permittivity_maetzler06
 from .water import water_permittivity
@@ -8,28 +9,28 @@
 @layer_properties("temperature", "liquid_water")
 def wetsnow_permittivity(frequency, temperature, liquid_water):
     """ calculate the dielectric constant of wet particule of ice using Bohren and Huffman 1983 according to Ya Qi Jin, eq 8-69, 1996 p282
-    
+
     :param frequency: frequency in Hz
     :param temperature: temperature in K
     :param liquid_water (fractional volume of water with respect to ice)
     :returns: Complex permittivity of pure ice
-    
+
     """
     # from http://books.google.com/books?id=Y_-113zIvgkC&pg=PA142&lpg=PA142&dq=effective+dielectric+constant+sphere+coated+small&source=bl&ots=ZVfwvkA0K1&sig=P7fHb0Jff8C-7-GrlEnWRZkkxY8&hl=en&ei=RHfDTrmjJYXj8AO3v7ScCw&sa=X&oi=book_result&ct=result&resnum=3&ved=0CDYQ6AEwAg#v=onepage&q=effective%20dielectric%20constant%20sphere%20coated%20small&f=false
     # see also: K L CHOPRA and G B REDDY, Praman.a- Optically selective coatings, J. Phys., Vol. 27, Nos 1 & 2, July & August 1986, pp. 193-217.
 
-    epsice = ice_permittivity_maetzler06(frequency,temperature)
+    epsice = ice_permittivity_maetzler06(frequency, temperature)
 
-    if liquid_water <= 0.0:
+    if np.all(liquid_water <= 0.0):
         return epsice
 
-    epswater = water_permittivity(frequency,temperature)
+    epswater = water_permittivity(frequency, temperature)
 
-    S = 1-liquid_water
+    S = 1 - liquid_water
 
-    Cplus = epsice + 2*epswater
-    Cminus = (epsice-epswater) * S
+    Cplus = epsice + 2 * epswater
+    Cminus = (epsice - epswater) * S
 
-    Ewi = (Cplus + 2*Cminus) / (Cplus - Cminus) * epswater
+    Ewi = (Cplus + 2 * Cminus) / (Cplus - Cminus) * epswater
 
-    return Ewi
+    return Ewi