GnuplotRB not working properly with Daru

[lokeshh]

I am having the following error with this notebook

You can click here for complete error message.

[ievgrafov]

Huh, seems very strange. As I can see from Daru sources, #keys is called on @relation_hash here https://github.com/v0dro/daru/blob/v0.1.2/lib/daru/index.rb#L122 which is initialized here https://github.com/v0dro/daru/blob/bf846e8340e81292a2bd313cb34f327f447d6225/lib/daru/index.rb#L57 .
@v0dro don't you have any thoughts, why it could be nil? As it seems for me, everything should be OK, if index is initialized properly.

[v0dro]

It's running fine on my computer!

I re-ran the entire notebook with daru 0.1.2 and gnuplotrb 0.3.0 and here's the cell that's giving you a problem:

However then I ran the whole notebook with gnuplotrb 0.3.3 and daru 0.1.2 and it gave the error that @lokeshh is talking about.

@dilcom I think the problem is that an update to daru in 0.1.2 has made it incompatible with that particular method in gnuplotrb.

[v0dro]

I think I found the problem. The method is:

    def get_daru_columns(data, cnt)
      new_opt = (2..cnt).to_a.join(':')
      if data.index.key(0).is_a?(DateTime) || data.index.key(0).is_a?(Numeric)
        "1:#{new_opt}"
      else
        "#{new_opt}:xtic(1)"
      end
    end

The problem might be that DateTimeIndex is no longer stored as a relation_hash and it does not contain a key method anymore. So it's reverting to the Daru::Index#key method since thats a super class of DateTimeIndex.

I'm just sending you a PR with a more flexible implementation that would not depend on future API changes.

[ievgrafov]

Great, thank you Sameer! My next question was "how to safely determine if index is a datetime", but you already solved it in pull request =). I'll release next minor version with this fix tomorrow.