multivariate polynomials

>From Gosei Furuya, Tue Jul 09, at 17:51:
 .
 .(C1) load("eigen")$
 .(C2) display2d:false $
 .(C3) H:matrix([_a,v,0],[v,b,0],[0,v,c])$
 .(C4) eigenvalues(H);
 .(D5) [[(-SQRT(_a^2-2*b*_a+4*v^2+b^2)+_a+b)/2,
 .     (SQRT(_a^2-2*b*_a+4*v^2+b^2)+_a+b)/2,c],[1,1,1]]
 .please down load diag.mac and jordan.dem from
 .cvsroot/maxima/share/contrib
 .(C6) load("diag.mac")$
 .(C7) jordan(H);
 .(D7) [[(-SQRT(_a^2-2*b*_a+4*v^2+b^2)+_a+b)/2,1],
 .       [(SQRT(_a^2-2*b*_a+4*v^2+b^2)+_a+b)/2,1],[c,1]]
 .

Thank you Gosei, but still no luck. 
Here enclosed my log file. 
A strange question mark appears, as diag.mac file is loaded.

Something wrong in my procedure?

thank you 

--
Paolo Pumilia




-- enc. ---------------------------------------------------
(C1) load("eigen");  
display2d:false ;

H : matrix( [ e1, V,      0],  
            [  V, e2-e1,  V],
            [  0,  V,   -e2] );

eigenvalues(H);
load("/usr/local/share/maxima/diag.mac");  

Warning - you are redefining the MACSYMA function EIGENVALUES
Warning - you are redefining the MACSYMA function EIGENVECTORS
(D1)                  /usr/lib/maxima-5.6/share/eigen.mc
(C2) 
(D2) FALSE
(C3) 
(D3) MATRIX([e1,V,0],[V,e2-e1,V],[0,V,-e2])
(C4) 
(D4) [[(-SQRT(3)*%I/2-1/2)*(SQRT(-32*V^6-(21*e2^2+6*e1*e2+21*e1^2)*V^4
                                        -(24*e2^4+6*e1*e2^3-36*e1^2*e2^2
                                                 +6*e1^3*e2+24*e1^4)
                                         *V^2-4*e2^6+12*e1*e2^5+3*e1^2*e2^4
                                        -26*e1^3*e2^3+3*e1^4*e2^2+12*e1^5*e2
                                        -4*e1^6)
                           /(6*SQRT(3))
                           +(e2*V^2+e1*(-V^2-e2^2)+e1^2*e2)/2)
                           ^(1/3)
        +(SQRT(3)*%I/2-1/2)*(2*V^2+e2^2-e1*e2+e1^2)
         /(3*(SQRT(-32*V^6-(21*e2^2+6*e1*e2+21*e1^2)*V^4
                          -(24*e2^4+6*e1*e2^3-36*e1^2*e2^2+6*e1^3*e2+24*e1^4)
                           *V^2-4*e2^6+12*e1*e2^5+3*e1^2*e2^4-26*e1^3*e2^3
                          +3*e1^4*e2^2+12*e1^5*e2-4*e1^6)
             /(6*SQRT(3))
                         +(e2*V^2+e1*(-V^2-e2^2)+e1^2*e2)/2)
                          ^(1/3)
        +(-SQRT(3)*%I/2-1/2)*(2*V^2+e2^2-e1*e2+e1^2)
         /(3*(SQRT(-32*V^6-(21*e2^2+6*e1*e2+21*e1^2)*V^4
                          -(24*e2^4+6*e1*e2^3-36*e1^2*e2^2+6*e1^3*e2+24*e1^4)
                           *V^2-4*e2^6+12*e1*e2^5+3*e1^2*e2^4-26*e1^3*e2^3
                          +3*e1^4*e2^2+12*e1^5*e2-4*e1^6)
             /(6*SQRT(3))
             +(e2*V^2+e1*(-V^2-e2^2)+e1^2*e2)/2)
             ^(1/3)),
       (SQRT(-32*V^6-(21*e2^2+6*e1*e2+21*e1^2)*V^4
                    -(24*e2^4+6*e1*e2^3-36*e1^2*e2^2+6*e1^3*e2+24*e1^4)*V^2
                    -4*e2^6+12*e1*e2^5+3*e1^2*e2^4-26*e1^3*e2^3+3*e1^4*e2^2
                    +12*e1^5*e2-4*e1^6)
        /(6*SQRT(3))
        +(e2*V^2+e1*(-V^2-e2^2)+e1^2*e2)/2)
        ^(1/3)
        +(2*V^2+e2^2-e1*e2+e1^2)/(3*(SQRT(
                                    -32*V^6-(21*e2^2+6*e1*e2+21*e1^2)*V^4
                                           -(24*e2^4+6*e1*e2^3-36*e1^2*e2^2
                                                    +6*e1^3*e2+24*e1^4)
                                            *V^2-4*e2^6+12*e1*e2^5+3*e1^2*e2^4
                                           -26*e1^3*e2^3+3*e1^4*e2^2
                                           +12*e1^5*e2-4*e1^6)
                                    /(6*SQRT(3))
                                    +(e2*V^2+e1*(-V^2-e2^2)+e1^2*e2)/2)
                                    ^(1/3))],[1,1,1]]
(C5) 
(D5) ?\/usr\/local\/share\/maxima\/diag\.mac
(C6) load("/usr/local/share/maxima/diag.mac");  

(D6) ?\/usr\/local\/share\/maxima\/diag\.mac
(C7) jordan(H);

quotient is not exact
#0: EIGENVECTORS(mat=MATRIX([e1,V,0],[V,e2-e1,V],[0,V,-e2]))
#1: jordan(mat=MATRIX([e1,V,0],[V,e2-e1,V],[0,V,-e2]))(diag.mac line 109)
 -- an error.  Quitting.  To debug this try DEBUGMODE(TRUE);)
(C8) 
 -- end enc. ---------------------------------------------------