Norm of real valued vector

[Hadi Lq]

Hi everyone

sage: R.<r,p>=RR[]

sage: rvec=vector([r*cos(p),r*sin(p)])

sage: rr=rvec.norm()

sage: rr.simplify_full()

sqrt((abs(cos(p))^2 + abs(sin(p))^2)*abs(r)^2)

which must gives me: r

How can I define real valued vector?

or How can I withdraw abs() function from norm?

Ubuntu 13.10

Sage Version 6.1.1, Release Date: 2014-02-04

[Alberto Verga]

You may try:

    r, p = var('r', 'p', domain = 'real')

    norm( vector([r*cos(p), r*sin(p)]) ).simplify_full()

[Alberto Verga]

add assume r>0

r,p = var('r', 'p', domain='real')

assume(r>0)

norm(vector([r*cos(p),r*sin(p)])).simplify_full()

to obtain r

Le samedi 19 avril 2014 20:53:53 UTC+2, Hadi Lq a écrit :