From b.rowlingson at lancaster.ac.uk  Fri Oct  3 18:11:25 2014
From: b.rowlingson at lancaster.ac.uk (Barry Rowlingson)
Date: Fri, 3 Oct 2014 17:11:25 +0100
Subject: [Rd] Intel Fortran compiler returns a -1 TRUE value
In-Reply-To: <a13204d90a5c4f5081b1b149a47dd92a@EX-1-HT0.lancs.local>
References: <CANVKczM_RkKjX_8U62Zb4BG=afNin3t=bjMb+CJKLEv6O2U-DQ@mail.gmail.com>
	<a13204d90a5c4f5081b1b149a47dd92a@EX-1-HT0.lancs.local>
Message-ID: <CANVKczOZynpkVBaFAvg9JB3rPka5nicY4mc4BxMAqx0hP3i5Xw@mail.gmail.com>

On Thu, Oct 2, 2014 at 4:25 PM, Ei-ji Nakama <nakama at ki.rim.or.jp> wrote:

> Hello
>
> > The value generated by Fortran's .TRUE. evaluates as "truthy" -- as in
> > all(z[[1]]) -- but is neither equal to nor identical to TRUE. Its numeric
> > conversion to -1 is most unusual, every other system I've tried converts
> to
> > +1.
>
> Please read the -fpscomp logicals option of ifort.
>

 Wow that's an interesting read, and the line

"Intel recommends that you avoid coding practices that
              depend on the internal representation of LOGICAL values"

says it all with regard to R and Fortran LOGICALS, I think!

Barry

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[Rd] Intel Fortran compiler returns a -1 TRUE value
Barry Rowlingson