demo implementation

demos/getting_started_1.py

@@ -46,7 +46,7 @@ def make_random_mask():
 
 
 if __name__ == '__main__':
-    np.random.seed(42)
+    ift.random.init(42)
 
     # Choose space on which the signal field is defined
     if len(sys.argv) == 2:

nifty6/__init__.py

 from .version import __version__
 
+from . import random
+
 from .domains.domain import Domain
 from .domains.structured_domain import StructuredDomain
 from .domains.unstructured_domain import UnstructuredDomain

nifty6/field.py

@@ -140,9 +140,9 @@ class Field(object):
         Field
             The newly created Field.
         """
-        from .random import Random
+        from . import random
         domain = DomainTuple.make(domain)
-        generator_function = getattr(Random, random_type)
+        generator_function = getattr(random, random_type)
         arr = generator_function(dtype=dtype, shape=domain.shape, **kwargs)
         return Field(domain, arr)
 

nifty6/random.py

@@ -11,16 +11,27 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
-# Copyright(C) 2013-2019 Max-Planck-Society
+# Copyright(C) 2013-2020 Max-Planck-Society
 #
 # NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik.
 
 import numpy as np
 
+_initialized = False
+
+def init(seed):
+    global _initialized
+    if _initialized:
+        print("WARNING: re-intializing random generator")
+        np.random.seed(seed)
+    else:
+        _initialized = True
+        np.random.seed(seed)
 
-class Random(object):
-    @staticmethod
 def pm1(dtype, shape):
+    global _initialized
+    if not _initialized:
+        raise RuntimeError("RNG not initialized")
     if np.issubdtype(dtype, np.complexfloating):
         x = np.array([1+0j, 0+1j, -1+0j, 0-1j], dtype=dtype)
         x = x[np.random.randint(4, size=shape)]
@@ -28,8 +39,10 @@ class Random(object):
         x = 2*np.random.randint(2, size=shape) - 1
     return x.astype(dtype, copy=False)
 
-    @staticmethod
 def normal(dtype, shape, mean=0., std=1.):
+    global _initialized
+    if not _initialized:
+        raise RuntimeError("RNG not initialized")
     if not (np.issubdtype(dtype, np.floating) or
             np.issubdtype(dtype, np.complexfloating)):
         raise TypeError("dtype must be float or complex")
@@ -48,8 +61,10 @@ class Random(object):
         x = np.random.normal(mean, std, shape).astype(dtype, copy=False)
     return x
 
-    @staticmethod
 def uniform(dtype, shape, low=0., high=1.):
+    global _initialized
+    if not _initialized:
+        raise RuntimeError("RNG not initialized")
     if not np.isscalar(low) or not np.isscalar(high):
         raise TypeError("low and high must be scalars")
     if (np.issubdtype(type(low), np.complexfloating) or