From: soxinbox <faker@...>
Date: 2005-10-22T12:07:00+09:00
Subject: Re: gnuplot on ruby

You will have to add something to change the search to look for pgnuplot.exe 
as there is no gnuplot.exe on windows. I have just started using this, but I 
agree it looks cool. I hope to use it to output some technical graphs. 
Thanks to those that created gnuplot and the ruby adaptation layer.

"Ara.T.Howard" <Ara.T.Howard@noaa.gov> wrote in message 
news:Pine.LNX.4.62.0510210836070.30900@harp.ngdc.noaa.gov...
> On Fri, 21 Oct 2005, gordon.j.miller@gmail.com wrote:
>
>> Ara.T.Howard wrote:
>>> On Fri, 21 Oct 2005, soxinbox wrote:
>>>
>>>> I installed gnuplot gem, and I am getting some syntax errors when I try 
>>>> to
>>>> run the samples on the projects web page.
>>>>
>>>>> ruby test.rb
>>>> c:/programs/ruby/lib/ruby/gems/1.8/gems/gnuplot-2.1/lib/gnuplot.rb:20:in
>>>> `popen': No such file or directory - which gnuplot (Errno::ENOENT)
>>>> from
>>>
>>> it looks like the code must do
>>>
>>>    IO::popen `which gnuplot`
>>>
>>> so either
>>>
>>>    - gnuplot is not on your system
>>>
>>>    - gnuplot is not in your path
>>>
>>> can you verify both of these?  from the shell do
>>>
>>>    ~:> which -a gnuplot
>>>
>>
>> Ara is completely correct with his diagnosis.  You have two choices, 
>> either
>> ensure that gnuplot is in your path or hardcode the path in the 
>> gnuplot.rb
>> file.  I've struggled for a number of years on how to improvie this but
>> haven't been able to come up with something better that satisfies my 
>> sense
>> of right and wrong.  Suggestions would be appreciated.
>
> maybe somthing like (un-tested):
>
>   def which bin
>     path = ENV['PATH'] # || ENV['WHAT_EVER_WINDOWS_PATH_VAR_IS']
>     path.split(File::PATH_SEPARATOR).each do |dir|
>       candidate = File::join dir, bin
>       return candidate if File::executable? candidate
>     end
>     return nil
>   end
>
>   gnuplot = ENV['RB_GNUPLOT'] || 'gnuplot'
>
>   gnuplot = which gnuplot or raise 'gnuplot is not in your path'
>
> or, if windows isn't a concern
>
>   gnuplot = `which gnuplot`
>
>   raise 'gnuplot not in your path' unless $? == 0
>
>   IO::popen gnuplot
>
>
> thanks for the good work on gnuplot btw - i've used in many times.
>
> cheers.
>
> -a
> -- 
> ===============================================================================
> | email :: ara [dot] t [dot] howard [at] noaa [dot] gov
> | phone :: 303.497.6469
> | anything that contradicts experience and logic should be abandoned.
> | -- h.h. the 14th dalai lama
> ===============================================================================
>