add numerical hygiene

src/scope/broadening.py

@@ -212,10 +212,12 @@ def I_darken_disk(x, y, epsilon):
     -------
         :res1: the intensity at that point on the disk.
     """
-    lon = np.arcsin(x)
-    lat = np.arcsin(y)
-
-    return I_darken(lon, lat, epsilon)
+    if x**2 + y**2 <= 1:
+        lon = np.arcsin(x)
+        lat = np.arcsin(y)
+        return I_darken(lon, lat, epsilon)
+    else:
+        return 0.0
 
 
 def I_darken_disk_integrated(x, y, epsilon):

src/scope/rm_effect.py

@@ -135,7 +135,9 @@ def occult_grid(occulted_grid, grid, planet_location, r_p):
     theta2 = planet_location[1]
 
     # calculate the distance between the planet and the grid points
-    r = np.sqrt(r1**2 + r2**2 - 2 * r1 * r2 * np.cos(theta1 - theta2))
+    r = np.sqrt(
+        np.clip(r1**2 + r2**2 - 2 * r1 * r2 * np.cos(theta1 - theta2), 0, None)
+    )
 
     # find the points where the planet is
     planet_points = np.where(r <= r_p)

src/scope/utils.py

@@ -180,7 +180,7 @@ def calc_limb_darkening(u1, u2, a, b, Rstar, ph, LD):
     """
     if LD:  # apply limb darkening. 1D style!
         x = (a * np.sin(2 * np.pi * ph)) / (Rstar * rsun)
-        mu = np.sqrt(1 - x**2 - b**2)
+        mu = np.sqrt(np.clip(1 - x**2 - b**2, 0, 1))
         if x**2 <= 1 - b**2:
             I = 1 - u1 * (1 - mu) - u2 * (1 - mu) ** 2
         else: