2017-03-03 22:49:55 +0100 | received badge | ● Popular Question (source) |
2014-11-16 12:35:12 +0100 | asked a question | Plotting parametric matrix discriminants Greetings, I am struggling with the problem concerting characteristic polynomial determinants. I'm intending to plot curves in the (a,b)-plane of parametric matrices, which signal the points of some eigenvalues being zero. To this end, I use the following code which however produces the error Printing the discriminant explicitly and then plotting it works fine although both quantities seem to be of the same type any ideas about what am I missing? |
2014-11-16 11:30:43 +0100 | received badge | ● Editor (source) |
2014-11-16 11:29:45 +0100 | asked a question | Plotting parametric matrix discriminants Hi, I intend to plot curves in the (a,b)-plane of parametric matrices, which signal the points of some eigenvalues being zero. To this end, I use the following code sage: var('a b') sage: A = matrix([[a+sqrt(-1)b,-1,0],[-1,0,-1],[0,-1,a-sqrt(-1)b]]) sage: p=A.charpoly('t') sage :d=p.discriminant() sage :region_plot(d>=0, (a,-4,1), (b,-4,1),incol='gray',figsize=5,axes=true) which however produces the error
to which I havent found sufficient answer/comment throughout the forum. Printing the discriminant explicitly and then plotting it works fine
although both quantities seem to be of the same type
any ideas about what am I missing? |