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[Bug fortran/33197] Fortran 2008: math functions
- From: "burnus at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 6 Mar 2008 13:50:06 -0000
- Subject: [Bug fortran/33197] Fortran 2008: math functions
- References: <bug-33197-13404@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #16 from burnus at gcc dot gnu dot org 2008-03-06 13:50 -------
(In reply to comment #15)
> > - Implementation of NORM2
> There are quite a few other new F2008 intrinsics, including other
> transformational intrinsics, so I think it's better to focus this PR on math
> intrinsics.
I would regard the L2 norm as mathematical
(http://mathworld.wolfram.com/L2-Norm.html)
y = NORM2(x) is for rank one arrays simply:
y = 0
do i=lbound(x,dim=1),ubound(x,dim=1)
y = y + x(i)**2
enddo
y = sqrt(y).
For a rank-one, size-two array it is the same as hypot(x(1),x(2)). Actually,
using hypot is an optimization one should do for size-2 arrays.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33197