Re: [R] Looking for package to solve for exponent using newton's method

And if you need some extra digits: require(Rmpfr) testfn-function(x){2^x+3^x-13} myint-c(mpfr(-5,precBits=1000),mpfr(5,precBits=1000)) myroot-unirootR(testfn, myint, tol=1e-30) myroot John Nash On 13-10-11 06:00 AM, r-help-requ...@r-project.org wrote: Message: 33 Date: Thu, 10 Oct 2013

[R] Looking for package to solve for exponent using newton's method

Hi, I'm looking for an R function/package that will let me solve problems of the type: 13 = 2^x + 3^x. The answer to this example is x = 2, but I'm looking for solutions when x isn't so easily determined. Looking around, it seems that there is no algebraic solution for x, unless I'm mistaken.

Re: [R] Looking for package to solve for exponent using newton's method

On 10/10/2013 2:39 PM, Ken Takagi wrote: Hi, I'm looking for an R function/package that will let me solve problems of the type: 13 = 2^x + 3^x. The answer to this example is x = 2, but I'm looking for solutions when x isn't so easily determined. Looking around, it seems that there is no

Re: [R] Looking for package to solve for exponent using newton's method

On 10-10-2013, at 20:39, Ken Takagi katak...@bu.edu wrote: Hi, I'm looking for an R function/package that will let me solve problems of the type: 13 = 2^x + 3^x. The answer to this example is x = 2, but I'm looking for solutions when x isn't so easily determined. Looking around, it

Re: [R] Looking for package to solve for exponent using newton's method

Thanks! That's just what I needed. __ R-help@r-project.org mailing list 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,

Re: [R] Looking for package to solve for exponent using newton's method

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