Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!haven!mimsy!oddjob!uxc!uxc.cso.uiuc.edu!uxe.cso.uiuc.edu!hirchert
From: hirchert@uxe.cso.uiuc.edu
Newsgroups: comp.lang.fortran
Subject: Re: Query: Complex data storage in new
Message-ID: <50500071@uxe.cso.uiuc.edu>
Date: 30 Aug 88 21:03:00 GMT
References: <2845@hubcap.UUCP>
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Nf-ID: #R:hubcap.UUCP:2845:uxe.cso.uiuc.edu:50500071:000:1176
Nf-From: uxe.cso.uiuc.edu!hirchert    Aug 30 16:03:00 1988


>For the record what constraints are imposed by the new standard
>for the storing of complex data?  Can a complex vector be stored
>as separate vectors or must the real and complex coefficients be
>stored contiguously?

One of the design constraints in the development of the draft Fortran 8x
standard was that it be upwards compatible with FORTRAN 77.  This means that
variables of the default COMPLEX types which are either equivalenced to
another type or in COMMON must be stored with real and imaginary parts
interleaved.  Proposals currently under consideration by X3J3 would extend
that requirement to nondefault COMPLEX types in the same storage association
contexts.  If your variables are not storage associated (and if your compiler
vendor is willing to support more than one way to store complex variables),
then storing the real and imaginary parts in separate vectors becomes possible.

>-- 
>Steve (really "D. E.") Stevenson           steve@hubcap.clemson.edu
>Department of Computer Science,            (803)656-5880.mabell
>Clemson University, Clemson, SC 29634-1906

Kurt W. Hirchert     hirchert@ncsa.uiuc.edu
National Center for Supercomputing Applications