Merge branch 'nifty6_this_and_that_and_changelog' into 'NIFTy_6'

Amend ChangeLog plus minor corrections along the way

See merge request !467

ChangeLog

@@ -4,6 +4,20 @@ Minimum Python version increased to 3.6
 =======================================
 
 
+New operators
+=============
+
+In addition to the below changes, the following operators were introduced:
+
+* UniformOperator: Transforms a Gaussian into a uniform distribution
+* VariableCovarianceGaussianEnergy: Energy operator for inferring covariances
+* MultiLinearEinsum: Multi-linear version of numpy's einsum with derivates
+* LinearEinsum: Linear version of numpy's einsum with one free field
+* PartialConjugate: Conjugates parts of a multi-field
+* SliceOperator: Geometry preserving mask operator
+* SplitOperator: Splits a single field into a multi-field
+* SwitchSpacesOperator: Permutes the domain entries of fields
+
 FFT convention adjusted
 =======================
 

nifty6/library/correlated_fields.py

@@ -61,7 +61,7 @@ def _lognormal_moments(mean, sig, N=0):
     if not np.all(sig > 0):
         raise ValueError("sig must be greater 0; got {!r}".format(sig))
 
-    logsig = np.sqrt(np.log((sig/mean)**2 + 1))
+    logsig = np.sqrt(np.log1p((sig/mean)**2))
     logmean = np.log(mean) - logsig**2/2
     return logmean, logsig
 

nifty6/multi_domain.py

@@ -37,12 +37,12 @@ class MultiDomain(object):
     """
     _domainCache = {}
 
-    def __init__(self, dict, _callingfrommake=False):
+    def __init__(self, dct, _callingfrommake=False):
         if not _callingfrommake:
             raise NotImplementedError(
                 'To create a MultiDomain call `MultiDomain.make()`.')
-        self._keys = tuple(sorted(dict.keys()))
-        self._domains = tuple(dict[key] for key in self._keys)
+        self._keys = tuple(sorted(dct.keys()))
+        self._domains = tuple(dct[key] for key in self._keys)
         self._idx = frozendict({key: i for i, key in enumerate(self._keys)})
 
     @staticmethod