Re: [Maxima-discuss] weird behavior of apply

[Gunter K. <gu...@pe...>]

Try using equals(y,0) as criterion of the comparison: "=" tests for structural equality and there are several ways of expressing zero.

Kind regards,

  Gunter.

On 29. September 2014 19:30:31 MESZ, Dimiter Prodanov <dim...@gm...> wrote:
>Hello,
>
>I define a function
>
>dy(y):=if y#0 and y#0.0 then  1/(2*y)   else 'nan;
>
>Then I wanted to substitute it's first argument by a value. The idea is
>to
>use pass a function having a variable number of arguments as a method
>parameter and then to evaluate it only on certain arguments.
>
>
>I stumbled on the following weird behavior:
>
>apply(dy, [y=0]);
>expt: undefined: 0 to a negative exponent.
> -- an error.
>
>also here
>
>at(dy(y),[y=0]);
>
>expt: undefined: 0 to a negative exponent.
> -- an error.
>
>while  dy(0) correctly evaluates to 'nan
>
>best regards,
>
>Dimiter
>
>
>------------------------------------------------------------------------
>
>------------------------------------------------------------------------------
>Slashdot TV.  Videos for Nerds.  Stuff that Matters.
>http://pubads.g.doubleclick.net/gampad/clk?id=160591471&iu=/4140/ostg.clktrk
>
>------------------------------------------------------------------------
>
>_______________________________________________
>Maxima-discuss mailing list
>Max...@li...
>https://lists.sourceforge.net/lists/listinfo/maxima-discuss

-- 
Diese Nachricht wurde von meinem Mobiltelefon mit Kaiten Mail gesendet.