Dr Lopez,

Thank you for your very interesting webinar on eigenpairs today. I especially valued your "aside" example of a matrix for which eigenvectors are "relatively simple," but which also has a "relatively simple" vector for which the magnitude is preserved, although not necessarily the direction. Your reply at the end of the program was very insightful, and I think it opens an interesting are of exploration.

Juan Tolosa Richard Stockton College, NJ

MAPLE does not have the capability of plotting nice (say, round) FILLED IN points, and "hollow" points are very often hard to distinguish in a window cluttered with graphs. I pointed this out to the Maple Support Team, and the following roundabout was suggested: > with(plottools): > c := disk([9,1.5], .2, color=black): > > d := disk([2,2.8], .2, color=black): > > display([c,d],scaling=constrained,view=[-10..10,-10..10]); > display(p1, p2, p3, p4, p5, p6,c, d, scaling=constrained,view=[-1..10,0..10]); > display(p1, p2, p3, p4, p5, p6,c, d,view=[-1..10,0..4]); However, the BIG inconvenient of this roundabout is that in reality it plots little circles. So, if the scales in both axes is strongly different (think of plotting monthly salaries, in dollars, against time, in months) you don't get round points, but very flat ellipses.