增加模块；增加主调用命令

prosail_method/modules/calctav.py

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+import numpy as np
+
+def calctav(alfa, nr):
+    """
+    Calculate average transmittance of isotropic light across a dielectric surface.
+    Translated from MATLAB version of calctav.m.
+
+    Parameters:
+        alfa : incidence angle in degrees (scalar or array)
+        nr   : refractive index of second medium (scalar or array of same shape as alfa)
+
+    Returns:
+        tav : average transmittance (same shape as alfa)
+    """
+    alfa = np.asarray(alfa)
+    nr = np.asarray(nr)
+    rd = np.pi / 180.0
+
+    n2 = nr ** 2
+    np_ = n2 + 1
+    nm = n2 - 1
+    a = ((nr + 1) ** 2) / 2
+    k = -((n2 - 1) ** 2) / 4
+    sa = np.sin(alfa * rd)
+
+    b1 = np.where(alfa != 90,
+                  np.sqrt((sa ** 2 - np_ / 2) ** 2 + k),
+                  0.0)
+    b2 = sa ** 2 - np_ / 2
+    b = b1 - b2
+    b3 = b ** 3
+    a3 = a ** 3
+
+    ts = (k ** 2 / (6 * b3) + k / b - b / 2) - (k ** 2 / (6 * a3) + k / a - a / 2)
+
+    tp1 = -2 * n2 * (b - a) / (np_ ** 2)
+    tp2 = -2 * n2 * np_ * np.log(b / a) / (nm ** 2)
+    tp3 = n2 * (1 / b - 1 / a) / 2
+    tp4 = 16 * n2 ** 2 * (n2 ** 2 + 1) * np.log((2 * np_ * b - nm ** 2) / (2 * np_ * a - nm ** 2)) / (np_ ** 3 * nm ** 2)
+    tp5 = 16 * n2 ** 3 * (1 / (2 * np_ * b - nm ** 2) - 1 / (2 * np_ * a - nm ** 2)) / (np_ ** 3)
+
+    tp = tp1 + tp2 + tp3 + tp4 + tp5
+    tav = (ts + tp) / (2 * sa ** 2)
+
+    return tav
+