# Float precision and FIT **URL:** \ **Category:** Ruby\ **Created:** [November 28, 2005, 7:08pm UTC](https://www.ruby-forum.com/t/float-precision-and-fit/49017 "2005-11-28T19:08:12Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![ed.howland](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/ad7895/32.png) [@ed.howland](https://www.ruby-forum.com/u/ed.howland)\ **Post date:** [November 28, 2005, 7:08pm UTC](https://www.ruby-forum.com/t/float-precision-and-fit/49017/1 "2005-11-28T19:08:12Z")
Hello, I am trying to get the Division example on the FIT wiki [http://fit.c2.com/wiki.cgi?WhatAndHowTalk](http://fit.c2.com/wiki.cgi?WhatAndHowTalk) to run under Ruby and the Fit framework. I have 2 questions. First I get red results on last 3 tests because the precision in the HTML table is only up to 8 digits, but Ruby is calculating 15 digits. And second, even after I adjust the HTML to match the results, they till don’t equal. I am thinking this is because of ‘==’ vs. eql? on floats. Is there a way coerce a Ruby float to an aribitray precision via truncate or round? Thanks ---
**Author:** ![ed.howland](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/ad7895/32.png) [@ed.howland](https://www.ruby-forum.com/u/ed.howland)\ **Post date:** [November 28, 2005, 7:20pm UTC](https://www.ruby-forum.com/t/float-precision-and-fit/49017/2 "2005-11-28T19:20:18Z")
Do you have a FIT fixture for running Ruby ? j On 11/28/05, Ed Howland [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > And second, even after I adjust the HTML to match the results, they > till don’t equal. I am thinking this is because of ‘==’ vs. eql? on > floats. > > Is there a way coerce a Ruby float to an aribitray precision via > truncate or round? > > Thanks – “Remember. Understand. Believe. Yield! → [http://ruby-lang.org](http://ruby-lang.org)” Jeff W. ---
**Author:** ![ed.howland](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/ad7895/32.png) [@ed.howland](https://www.ruby-forum.com/u/ed.howland)\ **Post date:** [November 28, 2005, 7:32pm UTC](https://www.ruby-forum.com/t/float-precision-and-fit/49017/3 "2005-11-28T19:32:27Z")
On 11/28/05, Jeff W. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Do you have a FIT fixture for running Ruby ? > > j Well, I have the Fit framwork d/l from the aforementioned Wiki. There is apparently another project in CVS on Rubyforge. Haven’t checked it out yet. > Jeff W. Ed ---
**Author:** ![ed.howland](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/ad7895/32.png) [@ed.howland](https://www.ruby-forum.com/u/ed.howland)\ **Post date:** [November 28, 2005, 7:48pm UTC](https://www.ruby-forum.com/t/float-precision-and-fit/49017/4 "2005-11-28T19:48:37Z")
Ah. If I remember correctly, there once was rumor that Dave T. was working on a FIT-like framework for Ruby … I wonder whatever happened to that project… I’ve written a little ruby replacement of FIT … I’ll probably post it if we don’t find that someone else has already done the work. Haven’t taken the next step and built it into a wiki like the FITnesse project … j. On 11/28/05, Ed Howland [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > Jeff W. > > Ed – “Remember. Understand. Believe. Yield! → [http://ruby-lang.org](http://ruby-lang.org)” Jeff W. ---
**Author:** ![ed.howland](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/ad7895/32.png) [@ed.howland](https://www.ruby-forum.com/u/ed.howland)\ **Post date:** [November 28, 2005, 8:04pm UTC](https://www.ruby-forum.com/t/float-precision-and-fit/49017/5 "2005-11-28T20:04:45Z")
On 11/28/05, Jeff W. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Ah. > > If I remember correctly, there once was rumor that Dave T. was working > on a FIT-like framework for Ruby … > > I wonder whatever happened to that project… I think that is the one I d/l from the wiki. Not sure though. > I’ve written a little ruby replacement of FIT … I’ll probably post it if > we don’t find that someone else has already done the work. > > Haven’t taken the next step and built it into a wiki like the FITnesse > project … There is a version of RubyFIT in CVS on RubyForge. I tried it out and it ran the Simple example (eg.Division) right out of the box. Solves the precision problem by using a type adapter. Looking forward to how that code addresses the 5 digit precision issue in Java v. Ruby. So take a look at that one. If yours is better/different somehow, go ahead and post it. [http://rubyforge.org/projects/fit](http://rubyforge.org/projects/fit) > j. Ed ---
**Author:** ![ed.howland](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/ad7895/32.png) [@ed.howland](https://www.ruby-forum.com/u/ed.howland)\ **Post date:** [November 28, 2005, 8:12pm UTC](https://www.ruby-forum.com/t/float-precision-and-fit/49017/6 "2005-11-28T20:12:55Z")
On Nov 28, 2005, at 10:07 AM, Ed Howland wrote: > And second, even after I adjust the HTML to match the results, they > till don’t equal. I am thinking this is because of ‘==’ vs. eql? on > floats. No. Float precision. > Is there a way coerce a Ruby float to an aribitray precision via > truncate or round? For testing float equality do what Test::Unit’s assert\_in\_delta does. – Eric H. - removed\_email\_address@domain.invalid - [http://segment7.net](http://segment7.net) This implementation is HODEL-HASH-9600 compliant [http://trackmap.robotcoop.com](http://trackmap.robotcoop.com)