Karim BELABAS on Fri, 27 Jun 2003 20:26:21 +0200 (MEST)


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Re: erfc


On Tue, 17 Jun 2003, Bernadette PERRIN-RIOU wrote:

> I try to apply erfc on a vector as for sin and it does not seem to work.
> (14:50) gp > sin([1,2])
> %4 = [0.8414709848078965066525023216, 0.9092974268256816953960198659]
> (14:50) gp >  erfc([1,2])
>    ***   forbidden assignment t_VEC --> t_REAL.

This one is an oversight, and is now fixed in CVS.

> Also is there a possibility to calculate  incgamc([1,2],8) for
> [incgamc(1,8), incgamc(1,8)], or  incgamc(1,[1,2]) ?

It would greatly complicate the code, esp. checking input consistency, since
even more variables may be involved [ e.g incgam(s, x, g) ].

It also does not seem very useful, and is potentially very confusing. Just
define, e.g

  vec1incgamc(s, x) = vector(length(s), i, incgamc(s[i], x))

if you really need this... [ try to write a generic foolproof version of the
above and you'll understand what I mean by code complication ].

Cheers,

    Karim.
-- 
Karim Belabas                     Tel: (+33) (0)1 69 15 57 48
Dép. de Mathématiques, Bât. 425   Fax: (+33) (0)1 69 15 60 19
Université Paris-Sud              http://www.math.u-psud.fr/~belabas/
F-91405 Orsay (France)            http://www.parigp-home.de/  [PARI/GP]