Re: [Axiom-developer] bug #10063 overview: Handling of power series

[Clifton Williamson]

This looks like an interpreter problem.  There is no
problem if you first coerce 'a' to be of type
UPXS(EXPR FLOAT,x,0):

(1) -> a := series sin x
(2) -> aFloat := a :: UPXS(EXPR FLOAT,x,0)
(3) -> aFloat * 1.0

When computing a * 1.0, if you do

)set mess bot on

you'll find that the interpreter is looking for a
function * with arguments (UPXS(EXPR INT,x,0),FLOAT)
just before Axiom crashes:

 Function Selection for *
      Arguments: (UPXS(EXPR INT,x,0),FLOAT) 
 
 
   >> System error:
   Caught fatal error [memory may be damaged]

You might also want to look at the messages you get
when you try to compute 1.0 * a.  In this case, the
punch line is:

 Function Selection for *
      Arguments: (FLOAT,UPXS(EXPR INT,x,0)) 
   -> no appropriate * found in Float 
   -> no appropriate * found in
UnivariatePuiseuxSeries(Expression Integer,x,0) 
 
   >> System error:
   Caught fatal error [memory may be damaged]



--- Vanuxem Grégory <address@hidden> wrote:

> Le lun 23/08/2004 à 01:02, root a écrit :
> > Greg,
> > 
> > Well, I wasn't looking for a new bug to chase but
> this is clearly one.
> > 
> > The bug is actually in the algebra somewhere
> rather than in the lisp.
> > The NAG version fails with the error msg:
> > 
> > +++ Error attempt to take the car of an atom: 0
> > 
> > Did you file this in the axiom bug list?
> > 
> > Tim
> 
> Yes, but 
> 
> 1<enter algEqual : ((0 . 0) 0 . 1)\((0 0 . 0) 0 1 .
> 0)\(|Expression|
> (|Float|)) 
> 1<enter compiledLookupCheck : =\((|Boolean|) $
> $)\#<vector 08eccc78> 
> 1>exit compiledLookupCheck : (#<compiled-function
> |EXPR;=;2$B;21|> .
> #<vector 08eccc78>) 
> 
> after SPADCALL (it's not traced) "=" in EXPR trigger
> the bug. 
> 
> algEqual : ((0 . 0) 0 . 1)\((0 0 . 0) 0 1 .
> 0)\(|Expression| (|Float|)) 
> ^^^^^^^^^^^^^^^ 
> I think above is not of type EXPR FLOAT. 
> 
> 
> >
>
====================================================================
> > Hi,
> > 
> > What do you think of this 'fatal 'bug?
> > 
> > 
> > 
> > It seems that the interpreter handles strangely
> the power series: 
> > 
> > a:= series sin(x); 
> > )di type % 
> > Type of value of %:
> UnivariatePuiseuxSeries(Expression Integer,x,0) 
> > a=a; 
> > )di type % 
> > Type of value of %: Equation Any 
> > 
> > If I coerce it... 
> > a:=a::UnivariatePuiseuxSeries(Expression
> Integer,x,0); 
> > a=a;
> > )di type % 
> > Type of value of %: Equation
> UnivariatePuiseuxSeries(Expression
> > Integer,x,0) 
> > ------------------------------------------------ 
> > Fatal bug: 
> > 
> > a:= series sin(x); 
> > a*1.0; 
> > >> System error: 
> > Caught fatal error [memory may be damaged] 
> > 
> > protected-symbol-warn called with (NIL) 
> > 
> > >From trace: 
> > It seems that the interpreter doesn't coerce one
> args 
> > in Expression (Float): 
> > 
> > 1<enter valueArgsEqual? :
> (|UnivariatePuiseuxSeries| (|Expression|
> > (|Integer|)) |x| ((0 . 0) 0 .
> 1))\(|UnivariatePuiseuxSeries|
> > (|Expression| (|Float|)) |x| ((0 . 0) 0 . 1)) 
> > 
> > ... 
> > 
> > And here: 
> > 
> > 1<enter algEqual : ((0 . 0) 0 . 1)\((0 0 . 0) 0 1
> . 0)\(|Expression|
> > (|Float|)) 
> > 1<enter compiledLookupCheck : =\((|Boolean|) $
> $)\#<vector 08eccc78> 
> > 1>exit compiledLookupCheck : (#<compiled-function
> |EXPR;=;2$B;21|> .
> > #<vector 08eccc78>) 
> > 
> > after SPADCALL (it's not traced) "=" in EXPR
> trigger the bug. 
> > 
> > algEqual : ((0 . 0) 0 . 1)\((0 0 . 0) 0 1 .
> 0)\(|Expression| (|Float|)) 
> > ^^^^^^^^^^^^^^^ 
> > I think above is not of type EXPR FLOAT. 
> > 
> > Cheers, Greg
> 
> 
> _______________________________________________
> Axiom-developer mailing list
> address@hidden
>
http://lists.nongnu.org/mailman/listinfo/axiom-developer
> 



                
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