Help required on sorting

[Dipti Iyengar]

Hi All,

   I ve to sort risks by "High" "Medium" "Low" "Info" and "Safe"

When I sort in the model it sorts in the alphabetical order which is not
what i want.

Tried adding a position to each of it as High -> 1 Medium -> 2 etc. and
then sorting by the position....but seems like too much of work

Any quicker way to do this?
--
Posted via http://www.ruby-forum.com/.

[Bertram Scharpf]

Hi,

Am Donnerstag, 09. Jul 2009, 18:46:40 +0900 schrieb Dipti Iyengar:
>    I ve to sort risks by "High" "Medium" "Low" "Info" and "Safe"
>
> When I sort in the model it sorts in the alphabetical order which is not
> what i want.

  ary.sort_by { |elem|                    
    case elem.risk
      when /high/i   then 5
      when /medium/i then 4
      when /low/i    then 3
      when /info/i   then 2
      when /safe/i   then 1
      else                0
    end
  }

Bertram


--
Bertram Scharpf
Stuttgart, Deutschland/Germany
http://www.bertram-scharpf.de

[David A. Black]

Hi --

On Thu, 9 Jul 2009, Dipti Iyengar wrote:

> Hi All,
>
>   I ve to sort risks by "High" "Medium" "Low" "Info" and "Safe"
>
> When I sort in the model it sorts in the alphabetical order which is not
> what i want.
>
> Tried adding a position to each of it as High -> 1 Medium -> 2 etc. and
> then sorting by the position....but seems like too much of work
>
> Any quicker way to do this?

You could do:

   LEVELS = %w{ High Medium Low Info Safe }

   sorted = risks.sort_by {|r| LEVELS.index(r.capitalize) }


David

--
David A. Black / Ruby Power and Light, LLC
Ruby/Rails consulting & training: http://www.rubypal.com
Now available: The Well-Grounded Rubyist (http://manning.com/black2)
Training! Intro to Ruby, with Black & Kastner, September 14-17
(More info: http://rubyurl.com/vmzN)

[Dipti Iyengar]

David A. Black wrote:

> Hi --
>
> On Thu, 9 Jul 2009, Dipti Iyengar wrote:
>
>> Any quicker way to do this?
> You could do:
>
>    LEVELS = %w{ High Medium Low Info Safe }
>
>    sorted = risks.sort_by {|r| LEVELS.index(r.capitalize) }
>
>
> David

Thanks a lot Bertram .... Worked like a charm....
Thanks a lot David...didn't try the solution as yet :)
--
Posted via http://www.ruby-forum.com/.

[Bertram Scharpf]

Hi,

Am Donnerstag, 09. Jul 2009, 19:11:46 +0900 schrieb David A. Black:
> On Thu, 9 Jul 2009, Dipti Iyengar wrote:
>>   I ve to sort risks by "High" "Medium" "Low" "Info" and "Safe"
>>
>> When I sort in the model it sorts in the alphabetical order which is not
>> what i want.
>
>   LEVELS = %w{ High Medium Low Info Safe }
>   sorted = risks.sort_by {|r| LEVELS.index(r.capitalize) }

Gosh, this is cool! I'm ashamed of my poor case approach.

Bertram


--
Bertram Scharpf
Stuttgart, Deutschland/Germany
http://www.bertram-scharpf.de

[David A. Black]

Hi --

On Thu, 9 Jul 2009, Bertram Scharpf wrote:

> Hi,
>
> Am Donnerstag, 09. Jul 2009, 19:11:46 +0900 schrieb David A. Black:
>> On Thu, 9 Jul 2009, Dipti Iyengar wrote:
>>>   I ve to sort risks by "High" "Medium" "Low" "Info" and "Safe"
>>>
>>> When I sort in the model it sorts in the alphabetical order which is not
>>> what i want.
>>
>>   LEVELS = %w{ High Medium Low Info Safe }
>>   sorted = risks.sort_by {|r| LEVELS.index(r.capitalize) }
>
> Gosh, this is cool! I'm ashamed of my poor case approach.

It comes from years of Ruby training where I use a deck of cards as
one of the main examples:

   RANKS = %w{ 2 3 4 5 6 7 8 9 10 j q k a }

   def <=>(other)
     RANKS.index(rank) <=> RANKS.index(other.rank)
   end

:-)


David

--
David A. Black / Ruby Power and Light, LLC
Ruby/Rails consulting & training: http://www.rubypal.com
Now available: The Well-Grounded Rubyist (http://manning.com/black2)
Training! Intro to Ruby, with Black & Kastner, September 14-17
(More info: http://rubyurl.com/vmzN)

[Joel VanderWerf]

David A. Black wrote:

> Hi --
>
> On Thu, 9 Jul 2009, Dipti Iyengar wrote:
>
>> Hi All,
>>
>>   I ve to sort risks by "High" "Medium" "Low" "Info" and "Safe"
>>
>> When I sort in the model it sorts in the alphabetical order which is not
>> what i want.
>>
>> Tried adding a position to each of it as High -> 1 Medium -> 2 etc. and
>> then sorting by the position....but seems like too much of work
>>
>> Any quicker way to do this?
>
> You could do:
>
>   LEVELS = %w{ High Medium Low Info Safe }
>
>   sorted = risks.sort_by {|r| LEVELS.index(r.capitalize) }

If there are a lot of levels, it might be more efficient to avoid the
linear search and use a hash. It's not necesarily faster in this case
with only 6 levels, but anyway...


LEVELS = %w{ High Medium Low Info Safe }
LEVEL_HASH = LEVELS.inject({}) {|h, lev| h[lev] = LEVELS.index(lev); h}

risks = LEVELS + LEVELS

sorted = risks.sort_by {|r| LEVEL_HASH[r.capitalize] }
p sorted


--
       vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407