some trivial updates

Author: julian-urban

fredipy/covariance.py

@@ -4,7 +4,6 @@
     from .kernels import Kernel
     from .constraints import LinearEquality
 
-from .operators import Integral, Identity, ConstMatrix, Derivative
 import numpy as np
 
 

fredipy/kernels.py

@@ -103,7 +103,7 @@ def make(
         Return matrix of shape (len(x), len(y)) with entries set to 1 where
         x == y and 0 otherwise. Identity matrix if vectors x and y are equal.
         """
-        return (x.reshape(-1,1) == y.reshape(1,-1)).astype(float)
+        return (make_column_vector(x) == make_row_vector(y)).astype(float)
 
 
 class RadialBasisFunction(Kernel):