#1676 error doing a Fourier transform

closed
nobody
5
2010-10-10
2009-05-24
No

(%i1) integrate(%pi*exp(-2*%pi*t)*exp(2*%pi*x*t*%i),t,minf,inf);
Maxima encountered a Lisp error:
Unhandled kernel in tvar-lim
Automatically continuing.
To reenable the Lisp debugger set *debugger-hook* to nil.

Discussion

  • Rich Hennessy

    Rich Hennessy - 2009-05-24

    I get this same error in my pwdefint() function in pw.mac. I don't think it is a problem with pwdefint(). See the second case.

    (%i1) pwdefint(%pi*exp(-2*%pi*abs(t))*exp(2*%pi*%i*x*t),t,minf,inf);
    Maxima encountered a Lisp error:
    Unhandled kernel in tvar-lim
    Automatically continuing.
    To reenable the Lisp debugger set *debugger-hook* to nil.

    case 2:

    (%i1) integrate(%pi*exp(-2*%pi*abs(t))*exp(2*%pi*%i*x*t),t,minf,inf);

    Maxima encountered a Lisp error:

    Unhandled kernel in tvar-lim

    Automatically continuing.
    To reenable the Lisp debugger set *debugger-hook* to nil.
    (%i2) load(abs_integrate);
    (%o2) C:/Maxima-5.18.1/share/maxima/5.18.1/share/contrib/integration/abs_integrate.mac
    (%i3) integrate(%pi*exp(-2*%pi*abs(t))*exp(2*%pi*%i*x*t),t,minf,inf);

    Maxima encountered a Lisp error:

    Unhandled kernel in tvar-lim

    Automatically continuing.
    To reenable the Lisp debugger set *debugger-hook* to nil.
    (%i4)

     
  • Raymond Toy

    Raymond Toy - 2009-07-07

    This no longer appears to happen in the CVS version. (The result isn't great since it contains a lot of limit expressions, but the Lisp error is gone. I did not check to see if the answer makes sense or not.)

    Marking as pending/worksforme

     
  • Raymond Toy

    Raymond Toy - 2009-07-07
    • status: open --> pending
     
  • SourceForge Robot

    This Tracker item was closed automatically by the system. It was
    previously set to a Pending status, and the original submitter
    did not respond within 14 days (the time period specified by
    the administrator of this Tracker).

     
  • SourceForge Robot

    • status: pending --> closed
     
  • Robert Dodier

    Robert Dodier - 2009-07-23

    Reopening this item. I still see it. Appears to be triggered because TVAR-LIM does not have a case for MPLUS expressions.

     
  • Robert Dodier

    Robert Dodier - 2009-07-23
    • status: closed --> open
     
  • Dieter Kaiser

    Dieter Kaiser - 2009-11-14

    For the integral of the bug report I get the following with Maxima 5.19post:

    A not fully evaluated solution for x > 0:

    (%i1) integrate(%pi*exp(-2*%pi*t)*exp(2*%pi*x*t*%i),t,minf,inf);
    Is x positive, negative, or zero?

    p;
    (%o1) %pi*(-('limit(2*%pi*%e^-(2*%pi*t)*x*sin(2*%pi*t*x)
    -2*%pi*%e^-(2*%pi*t)*cos(2*%pi*t*x),t,minf,plus))
    /(4*%pi^2*x^2+4*%pi^2)
    +('limit(2*%pi*%e^-(2*%pi*t)*x*sin(2*%pi*t*x)
    -2*%pi*%e^-(2*%pi*t)*cos(2*%pi*t*x),t,inf,minus))
    /(4*%pi^2*x^2+4*%pi^2)
    +%i*(('limit(-2*%pi*%e^-(2*%pi*t)*sin(2*%pi*t*x)
    -2*%pi*%e^-(2*%pi*t)*x*cos(2*%pi*t*x),t,inf,minus))
    /(4*%pi^2*x^2+4*%pi^2)
    -('limit(-2*%pi*%e^-(2*%pi*t)*sin(2*%pi*t*x)
    -2*%pi*%e^-(2*%pi*t)*x*cos(2*%pi*t*x),t,minf,plus))
    /(4*%pi^2*x^2+4*%pi^2)))

    Again a solution for x < 0:

    (%i2) integrate(%pi*exp(-2*%pi*t)*exp(2*%pi*x*t*%i),t,minf,inf);
    Is x positive, negative, or zero?

    n;
    (%o2) %pi*(-('limit(2*%pi*%e^-(2*%pi*t)*x*sin(2*%pi*t*x)
    -2*%pi*%e^-(2*%pi*t)*cos(2*%pi*t*x),t,minf,plus))
    /(4*%pi^2*x^2+4*%pi^2)
    +('limit(2*%pi*%e^-(2*%pi*t)*x*sin(2*%pi*t*x)
    -2*%pi*%e^-(2*%pi*t)*cos(2*%pi*t*x),t,inf,minus))
    /(4*%pi^2*x^2+4*%pi^2)
    +%i*(('limit(-2*%pi*%e^-(2*%pi*t)*sin(2*%pi*t*x)
    -2*%pi*%e^-(2*%pi*t)*x*cos(2*%pi*t*x),t,inf,minus))
    /(4*%pi^2*x^2+4*%pi^2)
    -('limit(-2*%pi*%e^-(2*%pi*t)*sin(2*%pi*t*x)
    -2*%pi*%e^-(2*%pi*t)*x*cos(2*%pi*t*x),t,minf,plus))
    /(4*%pi^2*x^2+4*%pi^2)))

    But a Lisp error for x = 0:

    (%i3) integrate(%pi*exp(-2*%pi*t)*exp(2*%pi*x*t*%i),t,minf,inf);
    Is x positive, negative, or zero?
    z;

    ** - Continuable Error
    Invalid trig kernel in tvar-lim
    If you continue (by typing 'continue'): Return from COMMON-LISP:BREAK loop
    The following restarts are also available:
    MACSYMA-QUIT :R1 Maxima top-level
    Break 1 [2]> :r1
    Maxima restarted.

    This could be the correct solution for x=0. For this case one factor of the integrand vanishs and the integral is divergent:

    (%i4) integrate(%pi*exp(-2*%pi*t),t,minf,inf);
    defint: integral is divergent.
    -- an error. To debug this try: debugmode(true);

    Setting the resolution to "none".

    Dieter Kaiser

     
  • Dieter Kaiser

    Dieter Kaiser - 2010-10-10

    Fixed in hayat.lisp revision 1.44.
    Closing this bug report as fixed.
    Dieter Kaiser

     
  • Dieter Kaiser

    Dieter Kaiser - 2010-10-10
    • status: open --> closed
     

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