MathGroup Archive 2004

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

Search the Archive

Re: newbie myHead question

  • To: mathgroup at smc.vnet.net
  • Subject: [mg47044] Re: newbie myHead question
  • From: drbob at bigfoot.com (Bobby R. Treat)
  • Date: Mon, 22 Mar 2004 05:18:59 -0500 (EST)
  • References: <c3h1jj$bc8$1@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

Here are a couple of methods.

m={{a,b},{a,b},{a,b}};
n=myHead@@m;
myHead@@Transpose@(List@@n)
Head[n]@@Transpose@(List@@n)

myHead[{a,a,a},{b,b,b}]
myHead[{a,a,a},{b,b,b}]

Bobby

János <janos.lobb at yale.edu> wrote in message news:<c3h1jj$bc8$1 at smc.vnet.net>...
> I have
> 
> m = {{a, b}, {a, b}, {a, b}}
> 
> When I apply Transpose to it, I will have
> 
> Transpose[m]
> 
> {{a, a, a}, {b, b, b}}
> 
> The FullForm of it is
> 
> List[List[a, a, a], List[b, b, b]]
> 
> Now, if I do
> 
> n = Apply[myHead, m]
> 
> I get
> 
> myHead[{a, b}, {a, b}, {a, b}]
> 
> If I apply Transpose to it, I get
> 
> Transpose[n]
> 
> Transpose[myHead[{a, b}, {a, b}, {a, b}]]
> 
> The FullForm of it
> 
> Transpose[myHead[List[a, b], List[a, b], List[a, b]]]
> 
> which is not that I need.  I need
> 
> myHead[{a,a,a},{b,b,b}]
> 
> or
> 
> myHead[List[a, a, a], List[b, b, b]]
> 
> What am I missing ?  What should I do to get myHead[{a,a,a},{b,b,b}] ?
> 
> Thanks ahead,
> 
> János
> -------------------------------------------------
> clear perl code is better than unclear awk code; but NOTHING comes 
> close to unclear perl code
> http://www.faqs.org/faqs/computer-lang/awk/faq/


  • Prev by Date: Re: newbie myHead question
  • Next by Date: Re: newbie myHead question
  • Previous by thread: Re: newbie myHead question
  • Next by thread: Re: newbie myHead question