fix(noise): RandomGenerator rename and other GaussianNoiseDataset bugs (

#106)

- randomgen 1.18 renamed RandomGenerator to Generator.
This commit renames Generator back to RandomGenerator on import
for synthesis.noise, in the same way as was done in analysis.delay.
- Fixes bug in how autocorrelations are being identified in GaussianNoiseDataset
- Fixes inconsistent variable name in mpi_random_seed
(both 'gen' and 'randomgen' are used to refer to the same variable)

draco/synthesis/noise.py

@@ -28,9 +28,14 @@
 
 import contextlib
 
-import randomgen
 import numpy as np
 
+try:
+    # For backwards compatibility
+    from randomgen import RandomGenerator
+except ImportError:
+    from randomgen import Generator as RandomGenerator
+
 from caput import config
 from caput.time import STELLAR_S
 from cora.util import nputil
@@ -103,18 +108,17 @@ def process(self, data):
         vis = data.vis[:]
 
         # create a random generator, and create a local seed state
-        rg = randomgen.generator.RandomGenerator()
+        rg = RandomGenerator()
 
-        with mpi_random_seed(self.seed, randomgen=rg) as rg:
+        with mpi_random_seed(self.seed, gen=rg) as rg:
             noise = rg.normal(
                 scale=np.sqrt(tools.invert_no_zero(data.weight[:]) / 2),
                 size=(2,) + data.weight[:].shape,
             )
             vis[:] = noise[0] + 1j * noise[1]
 
         for si, prod in enumerate(data.prodstack):
-            prod_inputs = data.prod[prod]
-            if prod_inputs[0] == prod_inputs[1]:
+            if prod[0] == prod[1]:
                 # This is an auto-correlation
                 vis[:, si].real *= 2 ** 0.5
                 vis[:, si].imag = 0.0
@@ -390,7 +394,7 @@ def draw_complex_wishart(C, n):
 
 
 @contextlib.contextmanager
-def mpi_random_seed(seed, extra=0, randomgen=None):
+def mpi_random_seed(seed, extra=0, gen=None):
     """Use a specific random seed for the numpy.random context or for the RandomGen context, and return to the original state on exit.
 
     This is designed to work for MPI computations, incrementing the actual seed
@@ -428,7 +432,7 @@ def mpi_random_seed(seed, extra=0, randomgen=None):
     np.random.seed(new_seed)
 
     # we will be setting the numpy.random context
-    if randomgen is None:
+    if gen is None:
         # Copy the old state for restoration later.
         old_state = np.random.get_state()