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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>The code in testing_ROI_Martin new.R all seems to work. So I am putting together all the examples for a section in Chapter 2, hopefully finish by tomorrow. But here is a tiny usability improvement needed in the first example with the new interface. The following works fine:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>pspec <- portfolio.spec(assets=funds)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>pspec <- add.constraint(portfolio=pspec, type="full_investment", enabled=TRUE)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>pspec <- add.constraint(portfolio=pspec, type="box", min=-Inf, max=Inf, enabled=TRUE)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>pspec <- add.objective_v2(portfolio=pspec, type="risk", name="var", enabled=TRUE)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>However, I had expected that the following would also work fine, but does not:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>pspec <- portfolio.spec(assets=funds)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>pspec <- add.constraint(portfolio=pspec, type="full_investment", enabled=TRUE)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>pspec <- add.objective_v2(portfolio=pspec, type="risk", name="var", enabled=TRUE)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p> </o:p></span></p><p class=MsoNormal>opt <- optimize.portfolio_v2(R=returns, portfolio=pspec, optimize_method="ROI")<o:p></o:p></p><p class=MsoNormal>Error in get_constraints(portfolio) : <o:p></o:p></p><p class=MsoNormal> Box constraints min and max are not enabled or passed in<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>There should be default argument values for box, min and max if not provided, i.e., if box is not provided and group constraints are not provided, it should assume an unconstrained portfolio except for the full investment constraint.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>Also, note the following behavior:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>> args(add.constraint)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>function (portfolio, type, enabled = FALSE, ..., indexnum = NULL) <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>NULL<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>Is it possible for args to result in additional arguments of function that will make more clear what they are? Or by design are we stuck with the “…” to indicate all the other arguments possible?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>Doug<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p> </o:p></span></p></div></body></html>