Article View: comp.std.c++
Article #1867Re: Std. c++ for number crunching.
From: Matt Austern
Date: Tue, 29 Aug 1995 19:03
Date: Tue, 29 Aug 1995 19:03
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2908 bytes
Distribution: In article <9508291233.AA14795@dhow.vr.dnv.no> helm@dhow.vr.dnv.no (Jens Bloch Helmers) writes: > Has the committee considered to include standardized math > libraries? (Linear Algebra, mathematical functions etc.) > > Does Std. c++ introduce features which make it easier > for a compiler to exploit parallel processing? > (Like the new array syntax improves Fortran) Yes and no. The draft standard does include a number of features that are of interest to people who do numerical programming (see, in particular, chapter 26, which describes the Numerics Library), but it is not as extensive as what you get in Fortran and there are still some major omissions. First, a brief summary of what the standard does include: complex numbers, the basic transcendental functions (for both real and complex arguments), methods of getting access to low-level details of the machine's representation of floating-point numbers, one-dimensional arrays of numeric types that are designed for easy vectorization, a rather extensive set of operations and auxiliary classes dealing with slices of those arrays, and generalized numeric operations on ordinary STL containers. Some of the main things that the standard does not include are libraries for specialized fields of numerical analysis (linear algebra, optimization, integration and quadrature, FFTs, etc.) and multidimensional arrays. My own opinion is that it's appropriate to leave out the specialized libraries, since it would be too hard to provide a standard that met everyone's needs. I regard the lack of a standard multidimensional array class, though, as an unfortunate omission. valarray<T> (and the associated auxiliary classes) provides a lot of the building blocks you need to write multidimensional arrays yourself, but that's no real substitute for a standardized class. This omission will make it harder to write portable programs. -- Matt Austern He showed his lower teeth. "We matt@physics.berkeley.edu all have flaws," he said, "and http://dogbert.lbl.gov/~matt mine is being wicked." --- [ comp.std.c++ is moderated. Submission address: std-c++@ncar.ucar.edu. Contact address: std-c++-request@ncar.ucar.edu. The moderation policy is summarized in http://dogbert.lbl.gov/~matt/std-c++/policy.html. ]
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Path: arc1-ca.pugleaf.net!128.32.155.1!matt From: matt@godzilla.EECS.Berkeley.EDU (Matt Austern) Newsgroups: comp.std.c++ Subject: Re: Std. c++ for number crunching. Date: 29 Aug 1995 19:03:29 GMT Organization: University of California at Berkeley (computational neuroscience) Approved: matt@physics10.Berkeley.EDU (Matt Austern) Message-ID: <MATT.95Aug29120329@physics10.Berkeley.EDU> References: <9508291233.AA14795@dhow.vr.dnv.no> Reply-To: matt@physics.Berkeley.EDU NNTP-Posting-Host: physics10.berkeley.edu