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Re: Interrogating lists of unequal lenghths

• To: mathgroup at smc.vnet.net
• Subject: [mg67394] Re: [mg67367] Interrogating lists of unequal lenghths
• From: gardyloo <gardyloo at mail.wsu.edu>
• Date: Wed, 21 Jun 2006 02:13:23 -0400 (EDT)
• References: <200606200615.CAA15916@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Hi, Kevin,

    If your list contains only one "sublevel" of lists (as in your
example), try mapping Length over the list. Something like

In[1]:=

y = {{1, 2}, {3, 4}, {5, 6}}

Out[1]=

{{1, 2}, {3, 4}, {5, 6}}

In[2]:=

Length /@ y

Out[2]=

{2, 2, 2}

x = {{1}, {2, 3}, {4, 5, 6, 7}}

Length /@ x

Out[3]=

{{1}, {2, 3}, {4, 5, 6, 7}}

Out[4]=

{1, 2, 4}

                  Hope that helps!
                                       C.O.

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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• References:
  • Interrogating lists of unequal lenghths
    • From: "kevin_jazz" <kevinbowman@mac.com>