Correct typos in comments

xqml/estimators.py

@@ -147,7 +147,7 @@ def El(invCAA, invCBB, Pl):
 
 def CrossWindowFunction(El, Pl):
     """
-    Compute mode-mixign matrix (Tegmark's window matrix)
+    Compute mode-mixing matrix (Tegmark's window matrix)
     Wll = Trace[invCAA.Pl.invCBB.Pl] = Trace[El.Pl]
 
     Parameters
@@ -182,7 +182,7 @@ def CrossWindowFunction(El, Pl):
 
 def CrossWindowFunctionLong(invCAA, invCBB, Pl):
     """
-    Compute mode-mixign matrix (Tegmark's window matrix)
+    Compute mode-mixing matrix (Tegmark's window matrix)
     Wll = Trace[invCAA.Pl.invCBB.Pl] = Trace[El.Pl]
 
     Parameters
@@ -438,4 +438,4 @@ if __name__ == "__main__":
     import doctest
     if np.__version__ >= "1.14.0":
         np.set_printoptions(legacy="1.13")
-    doctest.testmod()
\ No newline at end of file
+    doctest.testmod()