Debug checking

pystencils/backends/dot.py

 import graphviz
-from graphviz import Digraph, lang
+try:
+    from graphviz import Digraph
+    import graphviz.quoting as quote
+except ImportError:
+    from graphviz import Digraph
+    import graphviz.lang as quote
 from sympy.printing.printer import Printer
 
 
@@ -12,7 +17,7 @@ class DotPrinter(Printer):
         super(DotPrinter, self).__init__()
         self._node_to_str_function = node_to_str_function
         self.dot = Digraph(**kwargs)
-        self.dot.quote_edge = lang.quote
+        self.dot.quote_edge = quote.quote
 
     def _print_KernelFunction(self, func):
         self.dot.node(str(id(func)), style='filled', fillcolor='#a056db', label=self._node_to_str_function(func))

pystencils/display_utils.py

@@ -10,7 +10,12 @@ from pystencils.kernel_wrapper import KernelWrapper
 def to_dot(expr: sp.Expr, graph_style: Optional[Dict[str, Any]] = None, short=True):
     """Show a sympy or pystencils AST as dot graph"""
     from pystencils.astnodes import Node
-    import graphviz
+    try:
+        import graphviz
+    except ImportError:
+        print("graphviz is not installed. Visualizing the AST is not available")
+        return
+
     graph_style = {} if graph_style is None else graph_style
 
     if isinstance(expr, Node):

pystencils_tests/test_math_functions.py

@@ -33,7 +33,8 @@ def test_two_arguments(dtype, func, target):
     dh.run_kernel(kernel)
     dh.all_to_cpu()
 
-    np.testing.assert_allclose(dh.gather_array("x")[0, 0], float(func(1.0, 2.0).evalf()))
+    np.testing.assert_allclose(dh.gather_array("x")[0, 0], float(func(1.0, 2.0).evalf()),
+                               13 if dtype == 'float64' else 5)
 
 
 @pytest.mark.parametrize('dtype', ["float64", "float32"])

pystencils_tests/test_vectorization_specific.py

@@ -77,6 +77,7 @@ def test_strided(instruction_set, dtype):
                                                           default_number_float=npdtype)
             ast = ps.create_kernel(update_rule, config=config)
             assert len(warn) == 0
+            
     ps.show_code(ast)
     func = ast.compile()
     ref_func = ps.create_kernel(update_rule).compile()