Use copy when setting mean of vmf

Author: FlorianPfaff

pyrecest/distributions/hypersphere_subset/von_mises_fisher_distribution.py

@@ -23,7 +23,7 @@
     zeros,
 )
 from scipy.special import iv
-
+import copy
 from .abstract_hyperspherical_distribution import AbstractHypersphericalDistribution
 
 
@@ -127,11 +127,14 @@ def from_mean_resultant_vector(m):
 
     def mode(self):
         return self.mu
+    
+    def set_mean(self, new_mean):
+        self.set_mode(new_mean)
 
     def set_mode(self, new_mode):
         assert new_mode.shape == self.mu.shape
         dist = self
-        dist.mu = new_mode
+        dist.mu = copy.deepcopy(new_mode)
         return dist
 
     def multiply(self, other: "VonMisesFisherDistribution"):