Mathematica 9 is now available
Services & Resources / Wolfram Forums / MathGroup Archive
-----

MathGroup Archive 2008

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Tally

  • To: mathgroup at smc.vnet.net
  • Subject: [mg86925] Re: Tally
  • From: Michael Weyrauch <michael.weyrauch at gmx.de>
  • Date: Wed, 26 Mar 2008 04:54:45 -0500 (EST)
  • References: <fsa5eq$adg$1@smc.vnet.net>

Hello,

   I dont't think there is anything wrong with your code, but I know that
under certain conditions Tally does not work properly.

I postet a similar problem re Tally last November to Wolfram support, 
and I got the answer that Tally is not always working correctly.

I suggest you write your own Tally function, e.g. using Sow and Reap.
This works fast and perfect in my situations.

Michael Weyrauch


Armen Kocharyan schrieb:
> Dear Group,
> 
> I'm trying the following:
> 
> 
> *Dlist = {{{0,1},{0,1}},{{1,0},{1,0}},{{1,0},{0,1}},{{0,1},{1,0}}};*
> 
> *Tally[Dlist,(#1=== #2) \[Or] *
> 
> *            (#1[[1]][[1]]=== #2[[1]][[2]] \[And] *
> 
> *             #1[[1]][[2]]=== #2[[1]][[1]] \[And] *
> 
> *             #1[[2]][[1]]=== #2[[2]][[2]] \[And] *
> 
> *             #1[[2]][[2]]=== #2[[2]][[1]] )&]*
> 
> 
> 
> The output is:
> 
> *{{{{0,1},{0,1}},1},{{{1,0},{1,0}},1},{{{1,0},{0,1}},2}}*
> 
> instead of
> 
> *{{{{0,1},{0,1}},2},{{{1,0},{0,1}},2}}*
> 
> 
> 
> If I remove the last member from DList
> 
> *Dlist = {{{0,1},{0,1}},{{1,0},{1,0}},{{1,0},{0,1}}};*
> 
> then I got a correct answer
> 
> *{{{{0,1},{0,1}},2},{{{1,0},{0,1}},1}}.*
> 
> 
> 
> Is anything wrong with my original code?
> 
> 
> 
> Best regards,
> 
> Armen
> 
> 


  • Prev by Date: Another stylesheet question
  • Next by Date: Re: Mathlink: How do I pass arbitrary data from Mathematica to C?
  • Previous by thread: Tally
  • Next by thread: Re: Tally