I addition to the advice you have already received, you might have a look here, https://cran.r-project.org/web/views/Optimization.html to see if there might be tools to assist in your 'metasearch' . I wouldn't be surprised if that is a vain hope for the reasons you have already been given, but it can't hurt to look, right?
Cheers, Bert On Tue, Nov 15, 2022 at 6:46 AM Ebert,Timothy Aaron <[email protected]> wrote: > I would suggest treating initial values as hyperparameters. Try a range of > values to understand how your choice influences your outcome. Plot the > result. Eventually (I hope) you will get a feel for the right answer for > your specific type of data and you will be able to reduce the time needed > for this activity. > > If you want to be safe I would use the microbenchmark package to determine > program run time. If runtimes are short then > I might try a range of 0 to 10 in steps of 0.01 and see what happens. If > there is an interesting region I might then focus on that in finer steps. > > Tim > > -----Original Message----- > From: R-help <[email protected]> On Behalf Of ASHLIN VARKEY > Sent: Tuesday, November 15, 2022 2:49 AM > To: [email protected] > Subject: [R] Initial value choosing in nleqslv package > > [External Email] > > In my work, I use l-moments for estimation and obtain a system of > nonlinear equations. I am using the 'nleqslv' package in the R- program to > solve these equations but am struggling to choose initial values. Is there > any criteria to choose initial values in this package or is there any other > method to solve these equations? My system of equations are given below. > > simeqn=function(x){ > > y=numeric(4) > > y[1]=x[1]*(((gamma(1+x[2])*gamma(x[3]-x[2]))/gamma(x[3]))+((gamma(1- > x[2])*gamma(x[4]+x[2]))/gamma(x[4])))- 38353 > > > > y[2]=x[1]*gamma(1+x[2])*((gamma(x[3]-x[2])/gamma(x[3]))-(gamma(2*x[3]-x[2])/gamma(2*x[3]))-(gamma(x[4]+x[2])/gamma(x[4]))+(gamma(2*x[4]+x[2])/gamma(2*x[4])))- > 3759.473 > > > > y[3]=x[1]*gamma(1+x[2])*((gamma(x[3]-x[2])/gamma(x[3]))-(3*gamma(2*x[3]-x[2])/gamma(2*x[3]))+(2*gamma(3*x[3]-x[2])/gamma(3*x[3]))+(gamma(x[4]+x[2])/gamma(x[4]))-(3*gamma(2*x[4]+x[2])/gamma(2*x[4]))+(2*gamma(3*x[4]+x[2])/gamma(3*x[4])))- > 966.3958 > > y[4]= > > x[1]*gamma(1+x[2])*((gamma(x[3]-x[2])/gamma(x[3]))-(6*gamma(2*x[3]-x[2])/gamma(2*x[3]))+(10*gamma(3*x[3]-x[2])/gamma(3*x[3]))-(5*gamma(4*x[3]-x[2])/gamma(4*x[3]))-(gamma(x[4]+x[2])/gamma(x[4]))+(6*gamma(2*x[4]+x[2])/gamma(2*x[4]))-(10*gamma(3*x[4]+x[2])/gamma(3*x[4]))+(5*gamma(4*x[4]+x[2])/gamma(4*x[4])))- > 500.952 > > y > > } > > [[alternative HTML version deleted]] > > ______________________________________________ > [email protected] mailing list -- To UNSUBSCRIBE and more, see > > https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fstat.ethz.ch%2Fmailman%2Flistinfo%2Fr-help&data=05%7C01%7Ctebert%40ufl.edu%7C7119f0c53d984aed0be908dac7156d81%7C0d4da0f84a314d76ace60a62331e1b84%7C0%7C0%7C638041192349108654%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=E%2FVs%2FPCFnXV9LVsgg24SqBmb7LXB890OaIdqfoHjuFM%3D&reserved=0 > PLEASE do read the posting guide > https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.r-project.org%2Fposting-guide.html&data=05%7C01%7Ctebert%40ufl.edu%7C7119f0c53d984aed0be908dac7156d81%7C0d4da0f84a314d76ace60a62331e1b84%7C0%7C0%7C638041192349108654%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=A9pn7JDIrGgJJO0g2bdHmrYRo2UCO9yxMiGiOORO8HY%3D&reserved=0 > and provide commented, minimal, self-contained, reproducible code. > > ______________________________________________ > [email protected] mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > [[alternative HTML version deleted]] ______________________________________________ [email protected] mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
