Path: csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail From: Dennis Lee Bieber Newsgroups: comp.lang.python Subject: Re: Interfacing a dynamic shared library gives me different results in 2.7 versus 3.5 Date: Tue, 24 May 2016 20:14:23 -0400 Organization: IISS Elusive Unicorn Lines: 19 Message-ID: References: <1837656f-ef9a-4bcf-8074-c9565dd8c59a@googlegroups.com> <5744820e$0$1604$c3e8da3$5496439d@news.astraweb.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: news.uni-berlin.de 2Ubi0HAlnirCwjG52Q1vBgJ+PQFdHlIgp2As9byvPizA== Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.003 X-Spam-Evidence: '*H*': 0.99; '*S*': 0.00; 'convention.': 0.07; 'message-id:@4ax.com': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'subject:2.7': 0.09; 'subject:library': 0.09; 'wed,': 0.15; '2016': 0.16; 'in-memory': 0.16; 'numpy': 0.16; 'received:80.91.229.3': 0.16; 'received:io': 0.16; 'received:plane.gmane.org': 0.16; 'received:psf.io': 0.16; 'subject:versus': 0.16; "wouldn't": 0.16; 'url:home': 0.18; 'library': 0.20; 'along.': 0.22; 'ctypes': 0.22; 'passing': 0.23; 'header:X-Complaints-To:1': 0.26; 'chris': 0.26; 'question:': 0.29; 'array': 0.29; 'code': 0.30; 'certain': 0.31; 'could': 0.35; 'but': 0.36; 'basic': 0.36; 'to:addr:python-list': 0.36; 'subject:: ': 0.37; 'received:org': 0.37; 'charset:us-ascii': 0.37; 'to:addr:python.org': 0.40; 'some': 0.40; 'address': 0.61; 'skip:u 10': 0.61; 'series': 0.65; 'surprise': 0.72; '+1000,': 0.84; 'dennis': 0.91; 'subject:results': 0.91; 'received:108': 0.93 X-Injected-Via-Gmane: http://gmane.org/ X-Gmane-NNTP-Posting-Host: adsl-108-73-116-84.dsl.klmzmi.sbcglobal.net X-Newsreader: Forte Agent 6.00/32.1186 X-No-Archive: YES X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Mailman-Original-Message-ID: X-Mailman-Original-References: <1837656f-ef9a-4bcf-8074-c9565dd8c59a@googlegroups.com> <5744820e$0$1604$c3e8da3$5496439d@news.astraweb.com> Xref: csiph.com comp.lang.python:109094 On Wed, 25 May 2016 02:45:30 +1000, Chris Angelico declaimed the following: > >I'm not certain of the in-memory representation of a numpy array, but >it wouldn't surprise me if it's just a series of consecutive >ints/floats - which would be exactly what a C or Fortran library will >be expecting. So my understanding is that there's some basic ctypes >wrapper code to locate the base address of the array, and then it >passes that straight along. > That leads to the question: Row-major or Column-major... Could have a very significant affect taking a row-major array and passing it to code using a column-major convention. -- Wulfraed Dennis Lee Bieber AF6VN wlfraed@ix.netcom.com HTTP://wlfraed.home.netcom.com/