Added some long time markup

src/sage/geometry/polyhedron/base.py

@@ -1106,7 +1106,7 @@ def to_linear_program(self, solver=None, return_variable=False, base_ring=None):
             sage: p=polytopes.icosahedron(base_ring=AA)
             sage: lp, x = p.to_linear_program(return_variable=True)
             sage: lp.set_objective(x[0] + x[1] + x[2])
-            sage: lp.solve()
+            sage: lp.solve()  # long time
             1.309016994374948?
 
         TESTS::

src/sage/geometry/polyhedron/library.py

@@ -1375,7 +1375,7 @@ def six_hundred_cell(self, exact=False):
             sage: p600 = polytopes.six_hundred_cell()
             sage: p600
             A 4-dimensional polyhedron in RDF^4 defined as the convex hull of 120 vertices
-            sage: p600.f_vector()
+            sage: p600.f_vector()  # long time ~2sec
             (1, 120, 720, 1200, 600, 1)
 
         Computation with exact coordinates is currently too long to be useful::

src/sage/geometry/polyhedron/plot.py

@@ -77,7 +77,7 @@ def render_3d(projection, *args, **kwds):
         sage: p1 = Polyhedron(vertices=[[1,1,1]], rays=[[1,1,1]])
         sage: p2 = Polyhedron(vertices=[[2,0,0], [0,2,0], [0,0,2]])
         sage: p3 = Polyhedron(vertices=[[1,0,0], [0,1,0], [0,0,1]], rays=[[-1,-1,-1]])
-        sage: p1.projection().plot() + p2.projection().plot() + p3.projection().plot()
+        sage: p1.projection().plot() + p2.projection().plot() + p3.projection().plot()  # long time ~2sec
         Graphics3d Object
 
     It correctly handles various degenerate cases::
@@ -88,7 +88,8 @@ def render_3d(projection, *args, **kwds):
         Graphics3d Object
         sage: Polyhedron(vertices=[[1,1,1]], lines=[[0,1,0],[0,0,1]]).plot()                  # R^2 in R^3
         Graphics3d Object
-        sage: Polyhedron(rays=[[0,1,0],[0,0,1]], lines=[[1,0,0]]).plot()                      # quadrant wedge in R^2
+        sage: Polyhedron(rays=[[0,1,0],[0,0,1]], lines=[[1,0,0]]).plot()
+        # long time quadrant wedge in R^2
         Graphics3d Object
         sage: Polyhedron(rays=[[0,1,0]], lines=[[1,0,0]]).plot()                              # upper half plane in R^3
         Graphics3d Object
@@ -134,9 +135,9 @@ def render_4d(polyhedron, point_opts={}, line_opts={}, polygon_opts={}, projecti
         sage: poly = polytopes.twenty_four_cell()
         sage: poly
         A 4-dimensional polyhedron in QQ^4 defined as the convex hull of 24 vertices
-        sage: poly.plot()
+        sage: poly.plot()  # long time
         Graphics3d Object
-        sage: poly.plot(projection_direction=[2,5,11,17])
+        sage: poly.plot(projection_direction=[2,5,11,17])  # long time ~2sec
         Graphics3d Object
         sage: type( poly.plot() )
         <class 'sage.plot.plot3d.base.Graphics3dGroup'>