Hi, Im using some graphing software to produce charts which contain various lines. One line i need to produce is a power trend line from an array dataset. Has anyone had any experience of this in ruby? JB

on 2008-11-14 12:27

on 2008-11-16 19:30

> Im using some graphing software to produce charts which contain various > lines. One line i need to produce is a power trend line from an array > dataset. Has anyone had any experience of this in ruby? One approach would be to use the fitting libraries provided by the GSL: http://www.gnu.org/software/gsl/manual/html_node/L... To access this from Ruby you can use the Ruby GSL bindings : http://rb-gsl.rubyforge.org/ Another approach may be to use the Ruby/R interface RRRuby : http://rubyforge.org/projects/rsruby/ although, unless you have a compelling reason to use Ruby (such as integrating with existing code) you may find it better to use R directly (http://www.r-project.org/). If you have some sample data or code perhaps we can come up with some examples, Hope this helps, Chris

on 2008-11-17 00:15

-------- Original-Nachricht -------- > Datum: Fri, 14 Nov 2008 20:24:01 +0900 > Von: John Butler <johnnybutler7@gmail.com> > An: ruby-talk@ruby-lang.org > Betreff: Power Trend Line > Hi, > > Im using some graphing software to produce charts which contain various > lines. One line i need to produce is a power trend line from an array > dataset. Has anyone had any experience of this in ruby? > > JB > -- > Posted via http://www.ruby-forum.com/. Dear John, maybe gruff is for you ? http://nubyonrails.com/pages/gruff Best regards, Axel

on 2008-11-17 00:25

> maybe gruff is for you ? > > http://nubyonrails.com/pages/gruff I interpreted the original message to mean code to fit a, for example, polynomial of a given order to some data. It's been a while since I played with it but can Gruff do this ? Chris

on 2008-11-17 01:08

Dear Chris, >> Im using some graphing software to produce charts which contain various >> lines. One line i need to produce is a power trend line from an array >> dataset. > > I interpreted the original message to mean code to fit a, for example, > polynomial of a given order to some data. It's been a while since I > played with it but can Gruff do this ? No, I don't think so, it's just for graphing (and for lines, rather than polynomials) rather than fitting, for which the software you proposed can be used. Maybe you're right that the OP wanted some fitting algorithm. A good place to look for is "Linear Regression" (can be used also to determine coefficients of polynomials). There is an example for Rb-gsl here: http://rb-gsl.rubyforge.org/fit.html#2 , chapter 5 . Once you've calculated it, you can choose a nice graphing output software ... Best regards, Axel