2018-10-02 18:38:27 +0100 commented answer Graphing max function - unexpected behavior Very informative, thank you. 2018-10-02 18:37:44 +0100 received badge ● Scholar (source) 2018-10-02 18:37:43 +0100 received badge ● Supporter (source) 2018-10-01 17:04:33 +0100 received badge ● Self-Learner (source) 2018-10-01 17:04:33 +0100 received badge ● Teacher (source) 2018-10-01 15:27:55 +0100 received badge ● Student (source) 2018-10-01 15:20:58 +0100 answered a question Graphing max function - unexpected behavior Using one of the related questions that came up after I submitted, I think I found the correct way to get the expected plot: contour_plot(f,(x,-3,3),(y,-3,3))  However, this still doesn't work as expected: contour_plot(max(abs(x),abs(y)),(x,-3,3),(y,-3,3))  2018-10-01 15:20:58 +0100 asked a question Graphing max function - unexpected behavior My minimal working example is: (x,y) = var('x y') def f(x,y): return max(abs(x),abs(y)) table([[f(x,y) for y in range(-3,4)] for x in range(-3,4)])  The output is this table:  3 3 3 3 3 3 3 3 2 2 2 2 2 3 3 2 1 1 1 2 3 3 2 1 0 1 2 3 3 2 1 1 1 2 3 3 2 2 2 2 2 3 3 3 3 3 3 3 3  That looks like it ought to. But when I try contour_plot(f(x,y),(x,-3,3),(y,-3,3))  I get something that looks a lot different. It seems I don't have enough karma to upload the image, but its looks more like the one that would be associated to this table: table([[f(0,y) for y in range(-3,4)] for x in range(-3,4)]) 3 2 1 0 1 2 3 3 2 1 0 1 2 3 3 2 1 0 1 2 3 3 2 1 0 1 2 3 3 2 1 0 1 2 3 3 2 1 0 1 2 3 3 2 1 0 1 2 3  I have the issue isolated in a Sage worksheet on CoCalc. I don't have enough karma to include a link, either.