Closes #10. Adds example of unit tests. Fixes general folder naming.

atmPy/General/air.py

@@ -0,0 +1,69 @@
+import atmPy.general.gas_props as gp
+import atmPy.general.water as water
+
+
+class Air(gp.Gas):
+    def __init__(self, t=20.0, p=1013.25, **kwargs):
+        super(Air, self).__init__(t, p)
+
+        self._Rd = 287.05
+        self._Rv = 461.495
+        self.e = 0
+
+        if "ecal_meth" in kwargs:
+            self._wvObj = kwargs.ecal_meth
+        else:
+            self._wvObj = water.MurphyKoop()
+
+        if "e" in kwargs:
+            self.e = kwargs.e
+        elif "rh" in kwargs:
+            self.e = self._wvObj.ew(self.t) * kwargs['rh'] / 100
+        else:
+            self.e = 0
+
+    def cal_e(self, rh):
+        self.e = self._wvObj.ew(self.t) * rh / 100
+
+    def mu(self):
+
+        """
+        The following function defines viscosity as a function of T in P-s.
+
+        Parameters
+        ---------
+        T:temperature in degrees Celsius
+
+        Returns
+        -------
+        Viscosity in P-s
+        """
+
+        # Make sure that the temperature is a float
+        t = self.t + 273.15
+        c = 120.0  # Sutherland's constant
+        mu0 = 18.27e-6  # Reference viscocity
+        t0 = 291.15  # Reference temperature
+
+        return (c + t0) / (c + t) * (t / t0) ** 1.5 * mu0
+
+    def l(self):
+
+        """
+        Determine the mean free path of air.
+
+        Returns
+        -------
+        Mean free path of air in microns.
+        """
+
+        # Convert pressure to atmospheres
+        patm = float(self.p) / 1013.25
+        l0 = 0.066  # Reference mean free path at 1 atm
+
+        return l0 / patm
+
+    def rho(self):
+
+        tk = self.t + 273.15
+        return self.p * 100 / (self._Rd* tk) + self.e * 100 / (self._Rv * tk)

atmPy/General/gas_props.py

@@ -0,0 +1,35 @@
+import abc
+
+class Gas(object):
+    """
+    Generic object defining different properties of gasses.
+
+    Attributes
+    ----------
+    p:  float
+        Pressure in mb.
+    t:  float
+        Temperature in degrees Celsius.
+    """
+    __metaclass__ = abc.ABCMeta
+
+    def __init__(self, t=20, p=1013.25):
+        self.t = t
+        self.p = p
+
+    def __str__(self):
+        return "Gas object with T = " + str(self.t) + " and P = " + str(self.p) + "."
+
+    @abc.abstractmethod
+    def mu(self):
+        return 0
+
+    @abc.abstractmethod
+    def l(self):
+        return 0
+
+    @abc.abstractmethod
+    def rho(self):
+        return 0
+
+

atmPy/General/tests/test_air.py

@@ -0,0 +1,68 @@
+import atmPy.general.air as air
+
+from numpy import abs
+
+
+class TestAir(object):
+    def __init__(self):
+        self.a = air.Air()
+
+        self.mu_vals = {'T': [-5, 0, 10, 15, 25],
+                        'mu': [1.7105007E-5, 1.7362065e-5, 1.7869785E-5, 1.8120528E-5, 1.861598E-5]
+                        }
+
+        self.rho_vals = {'T': [0, 0, 0, 0,
+                               0, 0, 0, 0,
+                               0, 0, 0, 0,
+                               25, 25, 25, 25,
+                               25, 25, 25, 25,
+                               25, 25, 25, 25],
+                         'P': [200, 200, 200, 200,
+                               800, 800, 800, 800,
+                               1000, 1000, 1000, 1000,
+                               200, 200, 200, 200,
+                               800, 800, 800, 800,
+                               1000, 1000, 1000, 1000],
+                         'RH': [25, 50, 75, 90,
+                                25, 50, 75, 90,
+                                25, 50, 75, 90,
+                                25, 50, 75, 90,
+                                25, 50, 75, 90,
+                                25, 50, 75, 90],
+                         'rho': [0.254, 0.254, 0.253, 0.252,
+                                 1.020, 1.019, 1.018, 1.018,
+                                 1.275, 1.274, 1.273, 1.273,
+                                 0.230, 0.227, 0.223, 0.221,
+                                 0.931, 0.928, 0.924, 0.922,
+                                 1.165, 1.161, 1.158, 1.156
+                                 ]
+                         }
+
+    def test_muvals(self):
+        print('========= Testing Dynamic Viscocity Calculations =========')
+        print('   T       mu   ')
+        print('======= ========')
+
+        for e, i in enumerate(self.mu_vals['T']):
+            yield self.check_mu, i, self.mu_vals['mu'][e], 1e-3
+
+    def test_rhos(self):
+        print('========= Testing Density Calculations =========')
+        print('   T       P       RH       rho   ')
+        print('======= ======= ======== =========')
+
+        for e, i in enumerate(self.rho_vals['rho']):
+            yield self.check_rho, {'T': self.rho_vals['T'][e],
+                                   'P': self.rho_vals['P'][e],
+                                   'RH': self.rho_vals['RH'][e]}, i, 0.1
+
+    def check_mu(self, t, val, tol):
+        self.a.t = t
+        print(self.a.t, self.a.mu(), abs((val - self.a.mu()) / val))
+        assert abs((val - self.a.mu()) / val) < tol
+
+    def check_rho(self, atm, val, tol):
+        kwargs = {"rh": atm['RH']}
+        self.a = air.Air(atm['T'], atm['P'], **kwargs)
+        print(self.a.t, self.a.p, atm['RH'], val,  self.a.rho(), abs((val - self.a.rho()) / val))
+        assert abs((val - self.a.rho()) / val) < tol

atmPy/General/atmosphere.py → atmPy/General/water.py

@@ -128,73 +128,3 @@ def ew(self, t):
     def ei(self, t):
         t += 273.15
         return exp(9.550426 - 5723.265/t + 3.53068*log(t) - 0.00728332*t)/100
-
-
-class Gas(object):
-    """
-    Generic object defining different properties of gasses.
-
-    Attributes
-    ----------
-    p:  float
-        Pressure in mb.
-    t:  float
-        Temperature in degrees Celsius.
-    """
-    __metaclass__ = abc.ABCMeta
-
-    def __init__(self, t=20, p=1013.25):
-        self.t = t
-        self.p = p
-
-    def __str__(self):
-        return "Gas object with T = " + str(self.t) + " and P = " + str(self.p) + "."
-
-    @abc.abstractmethod
-    def mu(self): 
-        return 0
-
-    @abc.abstractmethod
-    def l(self):
-        return 0
-
-
-class Air(Gas):
-    def __init__(self, t=20.0, p=1013.25):
-        super(Air, self).__init__(t, p)
-
-    def mu(self):    
-        """
-        The following function defines viscosity as a function of T in P-s.
-        
-        Parameters
-        ---------
-        T:temperature in degrees Celsius
-        
-        Returns
-        -------
-        Viscosity in P-s
-        """
-
-        # Make sure that the temperature is a float
-        t = self.t + 273.15
-        c = 120.0       # Sutherland's constant
-        mu0 = 18.27e-6  # Reference viscocity
-        t0 = 291.15     # Reference temperature
-
-        return (c+t0)/(c+t)*(t/t0)**1.5*mu0
-
-    def l(self):  
-        """
-        Determine the mean free path of air.
-            
-        Returns
-        -------
-        Mean free path of air in microns.
-        """
-
-        # Convert pressure to atmospheres
-        patm = float(self.p)/1013.25
-        l0 = 0.066  # Reference mean free path at 1 atm
-
-        return l0/patm