#128 ode2 chokes on invalid input

closed
nobody
Lisp Core (472)
2
2006-06-26
2002-09-20
No

Current CVS with gcl/windows

(C1) ode2( (2*x*y-exp(-2*y))*'diff(y,x)=0, y, x);

Error: .
Fast links are on: do (si::use-fast-links nil) for debugging
Error signalled by MACSYMA-TOP-LEVEL.
Broken at MACSYMA-TOP-LEVEL. Type :H for Help.
MAXIMA>>

This is an example from maximabook.
I have included it in rtestode.mac, but commented it out.

Discussion

    • priority: 5 --> 2
    • summary: ode2 failure --> ode2 chokes on invalid input
     
  • Logged In: YES
    user_id=365569

    The ode is has a typo so desimp() simplifies the de to dy/dx,
    and then chokes. Need better error handling here.

    The correct equation is (2*x*y-exp(-2*y))*'diff(y,x)+y=0, and
    this works.

    The test is now enabled in rtestode.mac, and the priority of
    the bug has been lowered.

     
  • Robert Dodier
    Robert Dodier
    2006-06-26

    Logged In: YES
    user_id=501686

    Not observed in 5.9.1 nor in 5.9.3. Both return y = %c as
    the solution for ode2( (2*x*y-exp(-2*y))*'diff(y,x)=0, y, x); .

    Closing this report as fixed.

     
  • Robert Dodier
    Robert Dodier
    2006-06-26

    • status: open --> closed
    • labels: --> Lisp Core