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var('x y') vf = plot_vector_field((-.099858*x*(x^2+y^2+.0004)/(x^4+2*x^2*y^2+y^4+2*(x^2-y^2)*.0004+.0004^2),-.099858*y*(x^2+y^2-.0004)/(x^4+2*x^2*y^2+y^4+2*(x^2-y^2)*.0004+.0004^2)), (x,0,3), (y,0,2.5), aspect_ratio=1) show(vf)
