Merge pull request #64 from AOtools/infinite_screen_seed_fix

Fix bug, where seed in infinite screen had no effect

Author: Matthew Townson

aotools/turbulence/infinitephasescreen.py

@@ -178,8 +178,15 @@ def make_initial_screen(self):
         Makes the initial screen usign FFT method that can be extended 
         """
 
+        # phase screen will make it *really* random if no seed at all given.
+        # If a seed is here, screen must be repeatable wiht same seed
+        if self.random_seed is not None:
+            seed = numpy.random.randint(0, 2**32 -1)
+        else:
+            seed = None
+
         self._scrn = phasescreen.ft_phase_screen(
-            self.r0, self.stencil_length, self.pixel_scale, self.L0, 1e-10
+            self.r0, self.stencil_length, self.pixel_scale, self.L0, 1e-10, seed=seed
         )
 
         self._scrn = self._scrn[:, :self.nx_size]
@@ -274,6 +281,8 @@ def __init__(self, nx_size, pixel_scale, r0, L0, random_seed=None, n_columns=2):
         self.stencil_length_factor = 1
         self.stencil_length = self.nx_size
 
+        self.random_seed = random_seed
+
         if random_seed is not None:
             numpy.random.seed(random_seed)
 
@@ -380,6 +389,7 @@ def __init__(self, nx_size, pixel_scale, r0, L0, random_seed=None, stencil_lengt
         self.L0 = L0
         self.stencil_length_factor = stencil_length_factor
         self.stencil_length = stencil_length_factor * self.nx_size
+        self.random_seed = random_seed
 
         if random_seed is not None:
             numpy.random.seed(random_seed)