# non-linear fourth-order differential equations

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## non-linear fourth-order differential equations

 I need to solve a system of non-linear fourth-order differential equations. Is there a command which solves this system? Thanks in advance. ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
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## Re: non-linear fourth-order differential equations

 Hi Yanika, Please try ?uniroot and ?ployroot f <- function(x) x^4-16 uniroot(f, lower= -3, upper=0) polyroot(c(-16,0,0,0,1))
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## Re: non-linear fourth-order differential equations

 OP is asking about a system of fourth-order "differential" equations, whereas you are telling her how to solve a single, algebraic nonlinear equation. Take a look at package "deSolve", and the function `lsode' in that package for solving a system of nonlinear ODEs (given initial values). Ravi. ------------------------------------------------------- Ravi Varadhan, Ph.D. Assistant Professor, Division of Geriatric Medicine and Gerontology School of Medicine Johns Hopkins University Ph. (410) 502-2619 email: [hidden email] -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Wu Gong Sent: Sunday, November 28, 2010 6:31 PM To: [hidden email] Subject: Re: [R] non-linear fourth-order differential equations Hi Yanika, Please try ?uniroot and ?ployroot f <- function(x) x^4-16 uniroot(f, lower= -3, upper=0) polyroot(c(-16,0,0,0,1)) ----- A R learner. -- View this message in context: http://r.789695.n4.nabble.com/non-linear-fourth-order-differential-equations-tp3062805p3062894.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code. ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
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## Re: non-linear fourth-order differential equations

 Hi Ravi, Thank you for your correction. I hope I didn't mess up anything:) Cheers. Wu