Re: [R] Find zeros of analytic functions
Robin Hankin wrote: > > If iterative methods are appropriate, > it's perhaps worth pointing out that Newton-Rapheson > works nicely for complex functions. > Hmmm... I think there are many cases where Newton-Raphson diverges for complex functions, like those that generate beautiful fractals. Alberto Monteiro __ R-help@stat.math.ethz.ch 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, reproducible code.
Re: [R] Find zeros of analytic functions
>> Dear Partecipants to the list, > >> I am Enrico Foscolo, a student of the Faculty of Statistics, >> University of Bologna, >> and I am interested under consideration of the search of zeros of >> one function. >> I would want to write a code using the software R. >> I have already read the book "Computing the Zeros of Analytic >> Functions" (P. Kravanja and M. Van Barel, 2000) that speaks about >> this problem, computing a Fortran 90 code. >> Consequently, I would want to ask You if: >> - already exists a R code, > > I presume you mean analytic functions of a complex argument. Few R > packages use complex vectors, and none of those few do this to my > knowledge. > If iterative methods are appropriate, it's perhaps worth pointing out that Newton-Rapheson works nicely for complex functions. The "elliptic" package includes function newton.rapheson() for this, in addition to other utilities for analyzing complex functions. HTH -- Robin Hankin Uncertainty Analyst National Oceanography Centre, Southampton European Way, Southampton SO14 3ZH, UK tel 023-8059-7743 __ R-help@stat.math.ethz.ch 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, reproducible code.
Re: [R] Find zeros of analytic functions
There is no need to send this twice under different subject lines. On Mon, 16 Apr 2007, enrico.foscolo2 wrote: > Dear Partecipants to the list, > I am Enrico Foscolo, a student of the Faculty of Statistics, University of > Bologna, > and I am interested under consideration of the search of zeros of one > function. > I would want to write a code using the software R. > I have already read the book "Computing the Zeros of Analytic Functions" (P. > Kravanja and M. Van Barel, 2000) that speaks about this problem, computing a > Fortran 90 code. > Consequently, I would want to ask You if: > - already exists a R code, I presume you mean analytic functions of a complex argument. Few R packages use complex vectors, and none of those few do this to my knowledge. > - how can I recall a Fortran 90 function in R (Windows XP Operating System). This is covered in 'Writing R Extensions', section 1.2.3 in the version (2.5.0 beta) I looked at. > My aim is to write the code for complete my work about studying functions and > searching points of maximum and minimum (local and global). > Many thanks for any kind of help and for Your availability. > > Enrico Foscolo -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UKFax: +44 1865 272595 __ R-help@stat.math.ethz.ch 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, reproducible code.
[R] Find zeros of analytic functions
Dear Partecipants to the list, I am Enrico Foscolo, a student of the Faculty of Statistics, University of Bologna, and I am interested under consideration of the search of zeros of one function. I would want to write a code using the software R. I have already read the book "Computing the Zeros of Analytic Functions" (P. Kravanja and M. Van Barel, 2000) that speaks about this problem, computing a Fortran 90 code. Consequently, I would want to ask You if: - already exists a R code, - how can I recall a Fortran 90 function in R (Windows XP Operating System). My aim is to write the code for complete my work about studying functions and searching points of maximum and minimum (local and global). Many thanks for any kind of help and for Your availability. Enrico Foscolo -- Leggi GRATIS le tue mail con il telefonino i-modeĀ di Wind http://i-mode.wind.it/ __ R-help@stat.math.ethz.ch 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, reproducible code.
