ENH: Update python wrappers for r797_.

example/example.py

@@ -93,16 +93,16 @@
 
 
 
-print("########################## IAPWS G7-04 ##########################")
+print("########################## IAPWS R7-97 ##########################")
 Ts = np.asarray([-1.0, 25.0, 100.0, 200.0, 300.0, 360.0, 374.0])
 Ts = Ts + 273.15
 
 
-ps = np.asarray(pyiapws.r797.psat(Ts))
+ps = pyiapws.r797.psat(Ts)
 for i in range(Ts.size): 
     print(f"{Ts[i]:23.3f} K {ps[i]:23.3f} MPa.")
 
-Ts = np.asarray(pyiapws.r797.Tsat(ps))
+Ts = pyiapws.r797.Tsat(ps)
 for i in range(Ts.size): 
     print(f"{Ts[i]:23.3f} K {ps[i]:23.3f} MPa.")
 
@@ -114,10 +114,10 @@
 Ts = np.linspace(0.0, 370.0, 500)
 Ts = Ts + 273.15
 
-ps = np.asarray(pyiapws.r797.psat(Ts))
+ps = pyiapws.r797.psat(Ts)
 ax.plot(Ts, ps, "r-", label="ps(Ts)")
 
-Ts = np.asarray(pyiapws.r797.Tsat(ps))
+Ts = pyiapws.r797.Tsat(ps)
 ax.plot(Ts, ps, "b--", label="Ts(ps)")
 
 ax.legend()

py/src/pyiapws/g704.py

@@ -68,8 +68,10 @@ def kd(T: np.ndarray, gas: str, heavywater: bool=False)->Union[np.ndarray, float
     kd: float or 1d-array
         Adimensional liquid-vapor constant. 
     """
+    scalar = False
     if isinstance(T, (int, float)):
         T_ = np.asarray((T,), dtype="f8")
+        scalar = True
     elif isinstance(T, np.ndarray):
         if T.ndim == 1:
             T_ = np.asarray(T, dtype="f8")
@@ -83,7 +85,12 @@ def kd(T: np.ndarray, gas: str, heavywater: bool=False)->Union[np.ndarray, float
     gas_ = str(gas)
     heavywater_  = bool(heavywater)
 
-    return g704_.kd(T_, gas_, heavywater_)
+    k = g704_.kd(T_, gas_, heavywater_)
+
+    if scalar:
+        return k[0]
+    else:
+        return k
 
 
 def ngases(heavywater:bool=False)->int:

py/src/pyiapws/r797.py

@@ -1,2 +1,78 @@
 """IAPWS R797"""
-from .r797_ import *
+import array
+import numpy as np
+from . import r797_
+
+
+def psat(Ts):
+    """
+    Compute the saturation pressure at temperature Ts. 
+    Validity range 273.13 K <= Ts <= 647.096 K.
+
+    Parameters
+    ----------
+    Ts: int, float or 1d-array.
+        Saturation temperature in K.
+
+    Returns
+    -------
+    ps: float or 1d-array
+        Saturation pressure in MPa.
+    """
+    scalar = False
+    if isinstance(Ts, (int, float)):
+        Ts_ = np.asarray((Ts,), dtype="f8")
+        scalar = True
+    elif isinstance(Ts, np.ndarray):
+        if Ts.ndim == 1:
+            Ts_ = np.asarray(Ts, dtype="f8")
+        else:
+            raise TypeError("Ts must be a 1d-array of floats.")
+    elif isinstance(Ts, array.array):
+        Ts_ = np.asarray(Ts, dtype="f8")
+    else:
+        raise TypeError("Ts must be a 1d-array of floats.")
+
+    ps = np.asarray( r797_.psat(Ts_) )
+
+    if scalar:
+        return ps[0]
+    else:
+        return ps
+
+
+def Tsat(ps):
+    """
+    Compute the saturation temperature at pressure ps.
+    Validity range 611.213 Pa <= ps <= 22.064 MPa.
+
+    Parameters
+    ----------
+    ps: int, float or 1d-array.
+        Saturation pressure in MPa.
+
+    Returns
+    -------
+    Ts: float or 1d-array
+        Saturation temperatur in K.
+    """
+    scalar = False
+    if isinstance(ps, (int, float)):
+        ps_ = np.asarray((ps,), dtype="f8")
+        scalar = True
+    elif isinstance(ps, np.ndarray):
+        if ps.ndim == 1:
+            ps_ = np.asarray(ps, dtype="f8")
+        else:
+            raise TypeError("ps must be a 1d-array of floats.")
+    elif isinstance(ps, array.array):
+        ps_ = np.asarray(ps, dtype="f8")
+    else:
+        raise TypeError("ps must be a 1d-array of floats.")
+
+    Ts = np.asarray( r797_.Tsat(ps_) )
+
+    if scalar:
+        return Ts[0]
+    else:
+        return Ts