Fixed GPU compatibility of polynomial test problem

pySDC/implementations/problem_classes/polynomial_test_problem.py

@@ -28,8 +28,8 @@ class polynomial_testequation(Problem):
         # invoke super init, passing number of dofs, dtype_u and dtype_f
         super().__init__(init=(1, None, np.dtype('float64')))
 
-        self.rng = self.xp.random.RandomState(seed=seed)
-        self.poly = self.xp.polynomial.Polynomial(self.rng.rand(degree))
+        self.rng = np.random.RandomState(seed=seed)
+        self.poly = np.polynomial.Polynomial(self.rng.rand(degree))
         self._makeAttributeAndRegister('degree', 'seed', localVars=locals(), readOnly=True)
 
     def eval_f(self, u, t):
@@ -50,7 +50,7 @@ class polynomial_testequation(Problem):
         """
 
         f = self.dtype_f(self.init)
-        f[:] = self.poly.deriv(m=1)(t)
+        f[:] = self.xp.array(self.poly.deriv(m=1)(t))
         return f
 
     def solve_system(self, rhs, factor, u0, t):
@@ -95,7 +95,7 @@ class polynomial_testequation(Problem):
             The exact solution.
         """
         me = self.dtype_u(self.init)
-        me[:] = self.poly(t)
+        me[:] = self.xp.array(self.poly(t))
         return me
 
 
@@ -125,7 +125,7 @@ class polynomial_testequation_IMEX(polynomial_testequation):
         """
 
         f = self.dtype_f(self.init)
-        derivative = self.poly.deriv(m=1)(t)
+        derivative = self.xp.array(self.poly.deriv(m=1)(t))
         f.impl[:] = derivative / 2
         f.expl[:] = derivative / 2
         return f