Use circstd**2 for variance to ensure consistency across SciPy versions (#50)

* Calculate variance as stdev**2. Ensure consistency across SciPy versions

* Do not import circvar as it is not needed

Author: ale94mleon

MDRestraintsGenerator/datatypes.py

@@ -33,7 +33,7 @@
 from MDAnalysis.selections import gromacs as mda_gmx
 import numpy as np
 from scipy import stats
-from scipy.stats import circmean, circvar, circstd
+from scipy.stats import circmean, circstd
 from matplotlib import pyplot as plt
 
 
@@ -56,7 +56,8 @@ def analyze(self):
         if not self.periodic:
             self.mean = self.values.mean()
             self.stdev = self.values.std()
-            self.var = self.values.var()
+            # Same behavior as for periodic data
+            self.var = self.stdev**2
         else:
             p_high = 180
             if self.atype == "angle":
@@ -65,7 +66,9 @@ def analyze(self):
                 p_low = -180
             self.mean = circmean(self.values, low=p_low, high=p_high)
             self.stdev = circstd(self.values, low=p_low, high=p_high)
-            self.var = circvar(self.values, low=p_low, high=p_high)
+            # Use circstd**2 instead of circvar to
+            # have same behavior across SciPy versions
+            self.var = self.stdev**2
 
     def mean_squared(self):
         """Returns (value-mean)**2 """

setup.py

@@ -26,7 +26,7 @@
     install_requires=[
         'MDAnalysis>1.0.0',
         'numpy',
-        'scipy<1.8',
+        'scipy',
         'matplotlib',
     ],
 )