On Sun, Feb 27, 2011 at 10:16 PM, Dirk Eddelbuettel <e...@debian.org> wrote: > > Hi Paul, > > On 27 February 2011 at 21:54, Paul Johnson wrote: > | Suppose the administrator has the Atlas blas installed, as well as the > | revolution-mkl, and then also the GOTOblas. How does R--as you > | package it--select which one to use? > > These two or three distinct issues: >
Yes, that's what I intended to ask. I think you mistake me for somebody who doesn't understand that there are several options in system administration. I just wanted to know how you choose among several installed BLAS. From your comments below, I gather you don't choose, rather you uninstall the other deb packages entirely? > i) The package system has a mechanism to express and honour preferences, > that is how Atlas is chose in case it as well as reference Blas are > installed. Same for the different 'vi' commands from vim, nvi, ... or > emacsen > Yes, that's the "fiddling sym links in /etc/alternatives" approach that I mentioned in my previous email. Whether it is debian scripts or me typing at the keyboard, it is still just a directory full of symbolic links. And I don't necessarily trust a deb package to do that any more than I trust myself. > ii) MKL is different as Revo made it appear in a directory only R uses. > So different mechanism. > Right. As you mention, it puts itself in the special place that only R uses. R ignores Goto BLAS2 as long as the mkl blas is sitting there. Hence it appears absolutely necessary to fiddle the symbolic links to stop R from using mkl. Unless you just remove revolution-mkl package altogether. > iii) Goto is not formally packaged and part of the distro. I think the helper > package is so good that is does the preferences scheme too but I'd have > to check. For my gcbd project I scripted it such that exactly one is > present. Yes, but we were talking about Goto as you described it packaged, not in the abstract. In case anybody wonders, here's how gotoblas2-helper handles it. gotoblas2-helper manipulates the ld search path. It adds this file "00_gotoblas2.conf", hoping that it is the first in the alphabetical order among blas-related files in /etc/ld.so.conf.d. $ cat /etc/ld.so.conf.d/00_gotoblas2.conf /usr/lib/gotoblas2 That's a safe gamble, until somebody packages up atlas and puts in 00_atlas.conf. Oops :) > > | Following the R Install and Admin manual, Section A.3.1, I've built R > > That has *nothing* to do or say on Debian package and hence no bearing on > your question. It bears on my case, because I control which BLAS libraries are used by changing the symbolic links, in the way that the R manual describes. Without uninstalling the deb packages, I don't see how it can be done. So, in summary, I was just curious to know how people that use your R packages manage to choose among the several BLAS. pj -- Paul E. Johnson Professor, Political Science 1541 Lilac Lane, Room 504 University of Kansas _______________________________________________ R-SIG-Debian mailing list R-SIG-Debian@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-debian
