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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoPlainText>Brian and Ross (and anyone else who wishes to comment),<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Thanks for the late evening response. Good to allow both conventions wrt the sign of risk. Will check the leading portfolio and risk products for most frequent choice, and then we should go to with the majority. My priors are that the plus sign will win.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Much more importantly: I just started browsing the PortfolioAnalytics help files manual, slowly starting to refresh my memory of what little I understood last summer. Please see the attached version of August 26 (not the latest I know, but almost the last if not the last the Hezky edited)), where I have added a small number of comments here and there. See in particular my comments on optimize.portfolio. It would be very helpful if the unfinished business of making ROI invisible to the user is taken care of, and soon we just have solve.QP and Rglpk_solve_LP as optimizer choice arguments. Even before getting all the constraint object changes, because then I could check running my solve.QP and Rglpk_solve_LP based examples (Ross you are quite familiar with these) run via optimize.portfolio and box constraints. Then come back to group constraints when they are implemented.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Will keep browsing the manual, and try to understand what is going on. Brian, I don’t know if you (and Ross) can manage, but examples at the end of each help file would be truly helpful (no pun intended).<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Thanks,<o:p></o:p></p><p class=MsoPlainText>Doug<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>P.S. Brian, I hope you didn’t hear my phone call at 11:15 or so – I thought you were still live on email and then realized that almost 30 minutes had passed and you had probably crashed. <o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>-----Original Message-----<br>From: gsoc-porta-bounces@lists.r-forge.r-project.org [mailto:gsoc-porta-bounces@lists.r-forge.r-project.org] On Behalf Of Brian G. Peterson<br>Sent: Friday, June 21, 2013 8:55 PM<br>To: gsoc-porta@r-forge.wu-wien.ac.at<br>Subject: Re: [GSoC-PortA] Quick question on multipliers and constrained_objective()</p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>On 06/21/2013 10:44 PM, Doug Martin wrote:<o:p></o:p></p><p class=MsoPlainText>> Small comment: a lot (if not most) literature on risk takes risk as a <o:p></o:p></p><p class=MsoPlainText>> positive number, so puts a minus sign on the VaR quantile, etc. I <o:p></o:p></p><p class=MsoPlainText>> previously noticed that PerformanceAnalytics takes risk as negative, <o:p></o:p></p><p class=MsoPlainText>> had the thought to change that.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>PerformanceAnalytics allows it either way, user's choice.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Risk is risk of *loss*. Period.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Now, the math is sometimes/often easier with a positive number, I admit, but it's typical for risk reports on real portfolios to describe those risks as negative numbers.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>So we allow either.<o:p></o:p></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Cheers,<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Brian<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>--<o:p></o:p></p><p class=MsoPlainText>Brian G. Peterson<o:p></o:p></p><p class=MsoPlainText><a href="http://braverock.com/brian/"><span style='color:windowtext;text-decoration:none'>http://braverock.com/brian/</span></a><o:p></o:p></p><p class=MsoPlainText>Ph: 773-459-4973<o:p></o:p></p><p class=MsoPlainText>IM: bgpbraverock<o:p></o:p></p><p class=MsoPlainText>_______________________________________________<o:p></o:p></p><p class=MsoPlainText>GSoC-PortA mailing list<o:p></o:p></p><p class=MsoPlainText><a href="mailto:GSoC-PortA@lists.r-forge.r-project.org"><span style='color:windowtext;text-decoration:none'>GSoC-PortA@lists.r-forge.r-project.org</span></a><o:p></o:p></p><p class=MsoPlainText><a href="http://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/gsoc-porta"><span style='color:windowtext;text-decoration:none'>http://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/gsoc-porta</span></a><o:p></o:p></p></div></body></html>