alt_eigen more info



Ick--this bug seems to come from nullspace, not something directly in alt_eign.mac.   I see that alt_eigen_h sets
ratmx to true. Changing that to ratmx :  false eliminates these failures at least with:

  (%i4) build_info();
  Maxima version: 5.25.1
   Maxima build date: 9:23 9/6/2011
   Host type: i686-pc-mingw32
   Lisp implementation type: Clozure Common Lisp
   Lisp implementation version: Version 1.7-r14925M  (WindowsX8632)

We need to isolate this bug better; here is a start:

(%i1) m : matrix([0,-(2*%i*(%i+1))/(2*%i+1),0,-(2*%i*(%i+1))/(2*%i+1)],[(2*%i*(%i+1))/(2*%i+1),0,(2*%i*(%i+1))/(2*%i+1),0],[0,-(2*%i*(%i+1))/(2*%i+1),0,-(2*%i*(%i+1))/(2*%i+1)],[(2*%i*(%i+1))/(2*%i+1),0,(2*%i*(%i+1))/(2*%i+1),0]);

(%o1) matrix([0,-(2*%i*(%i+1))/(2*%i+1),0,-(2*%i*(%i+1))/(2*%i+1)],[(2*%i*(%i+1))/(2*%i+1),0,(2*%i*(%i+1))/(2*%i+1),0],[0,-(2*%i*(%i+1))/(2*%i+1),0,-(2*%i*(%i+1))/(2*%i+1)],[(2*%i*(%i+1))/(2*%i+1),0,(2*%i*(%i+1))/(2*%i+1),0])

Likely OK (at least no error)

(%i5) nullspace(m), ratmx : false;
(%o5) span(matrix([0],[-24*%i-32],[0],[24*%i+32]),matrix([16-8*%i],[0],[8*%i-16],[0]))

Nasty bug:

(%i6) nullspace(m), ratmx : true;
Maxima encountered a Lisp error:
 value #:%I4173 is not of the expected type LIST.
Automatically continuing.
To enable the Lisp debugger set *debugger-hook* to nil.


--Barton

________________________________________

Hi,

More info on
rtest_alt_eigen.mac

windows,ccl,maxima 5.25.0  The same tests fail:  64,65,78,79

windows,gcl, maxima 5.28.0  All tests pass.

best,
John

_______________________________________________