Karim Belabas on Wed, 23 Mar 2016 12:10:40 +0100

 Re: Proposal to extend primes()

```* Jeroen Demeyer [2016-03-23 12:04]:
> On 2016-03-16 10:32, Karim Belabas wrote:
> >Currently a single argument describes the interval (as in e.g. polrealroots),
>
> I guess you mean polsturm().

polrootsreal(), sorry. (Which covers polsturm() as well.)

> But that actually does support polsturm(pol, a, b) as well as
> polsturm(pol, [a,b]). So the following are equivalent:
>
> gp> polsturm(x^3+1,[-oo,1])
> %1 = 1
> gp> polsturm(x^3+1,,1)
> %2 = 1

We still support the old syntax in %2, but it is now deprecated (and no longer
documented):

(12:06) gp > ??polsturm
polsturm(T,{ab}):

Number of real roots of the real squarefree polynomial T. If the argument ab
is present,  it must be a vector [a,b] with two real components (of type t_INT,
t_REAL,   t_FRAC  or  t_INFINITY)   and we count roots belonging to that closed
interval. [...]

(12:07) gp > ??polrootsreal
polrootsreal(T, {ab}):

Real  roots  of the polynomial T with rational coefficients,  multiple roots
being  included  according  to  their  multiplicity.   The roots are given to a
relative  accuracy of realprecision.   If argument ab is present,  it must be a
vector [a,b] with two components (of type t_INT,  t_FRAC or t_INFINITY)  and we
restrict to roots belonging to that closed interval. [...]

etc.

Cheers,

K.B.
--
Karim Belabas, IMB (UMR 5251)  Tel: (+33) (0)5 40 00 26 17
Universite de Bordeaux         Fax: (+33) (0)5 40 00 69 50
351, cours de la Liberation    http://www.math.u-bordeaux.fr/~kbelabas/
F-33405 Talence (France)       http://pari.math.u-bordeaux.fr/  [PARI/GP]
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