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Re: Interrogating lists of unequal lenghths

  • To: mathgroup at smc.vnet.net
  • Subject: [mg67380] Re: Interrogating lists of unequal lenghths
  • From: bghiggins at ucdavis.edu
  • Date: Wed, 21 Jun 2006 02:12:38 -0400 (EDT)
  • References: <e784k6$fq5$1@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

Try these methods

In[3]:=
x/.{a__Integer}:>Length[{a}]

Out[3]=
{1,2,4}

In[4]:=
Map[Length,x]

Out[4]=
{1,2,4}


Cheers,

Brian

kevin_jazz wrote:
> I'm trying to understand how to assess the dimensions of a list
> containing elements of unequal length.
> Let's say I have the list with elements of equal sizes
>
> In[12]:=
> y={{1,2},{3,4},{5,6}}
>
> Out[12]=
> {{1,2},{3,4},{5,6}}
>
> In[13]:=
> Dimensions[y]
>
> Out[13]=
> {3,2}
>
> Using the Dimensions function I can determine the size of the resulting
> array. If, on the other hand, I set up the following list
>
> In[5]:=
> x={{1},{2,3},{4,5,6,7}}
>
> In[6]:=
> Dimensions[x]
>
> Out[6]=
> {3}
>
> The Dimensions command tells me I have only 3 elements.  But, I need
> some way to figure out that the first sublist has length 1, second has
> length 2, and the third has length 4 in some automated fashion. I've
> looked through the other commands like Depth and Length but I don't see
> anything that does this.
> 
> What's the right to do it? 
> 
> Thanks,
> 
> Kevin


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