plot error: No X11 DISPLAY variable was set

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Hi, I have to make a plot of the following formula

x,y=var('x, y')
plot3d((x^2)*y-x*y+x*y^3,0,5)

but I obtain error message

/usr/lib64/python2.7/site-packages/sage/plot/plot3d/parametric_plot3d.py\ :704: DeprecationWarning: Unnamed ranges for more than one variable is deprecated and will be removed from a future release of Sage; you can used named ranges instead, like (x,0,2) See http://trac.sagemath.org/7008 for details. g, ranges = setup_for_eval_on_grid(f, [urange,vrange], plot_points) Exception in thread "main" java.lang.ExceptionInInitializerError Caused by: java.awt.HeadlessException: No X11 DISPLAY variable was set, but this program performed an operation which requires it. at sun.awt.HeadlessToolkit.getScreenSize(HeadlessToolkit.java:284) at org.openscience.jmol.app.jmolpanel.JmolPanel.<clinit>(JmolPanel.ja\ va:173) /usr/lib64/python2.7/site-packages/sage/repl/rich_output/display_manager\ .py:570: RichReprWarning: Exception in _rich_repr_ while displaying object: Jmol failed to create file '/home/sage/.sage/temp/host/1582/dir_0OP2db/preview.png', see '/home/sage/.sage/temp/host/1582/tmp_4sBlqC.txt' for details RichReprWarning, Graphics3d Object</clinit>