Re: count the number of sub-list in a list

*To*: mathgroup at smc.vnet.net*Subject*: [mg122241] Re: count the number of sub-list in a list*From*: Bill Rowe <readnews at sbcglobal.net>*Date*: Sat, 22 Oct 2011 06:06:10 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

On 10/21/11 at 7:28 AM, hitphyopt at gmail.com (Gy Peng) wrote: >I have a list like: <array snipped> >I consider each of {{*, *, *}, {*, *, *}, {*,*,*}} is one single >element, so how could I count how many element in the whole list? >Thank you very much! Using data to be your array In[17]:= Times @@ Drop[Dimensions[data], -2] Out[17]= 16 Here, I use the fact the element you want to count is a n x m array. So, the last two values in the list returned by Dimensions will be the dimensions of the element. Dropping the last two values gives the dimensions of an array of n x m elements. So, the product is the number of those m x n elements. Equivalently, you could compute the total number of entries at the lowest level then divide by the number of entries in you element, i.e., In[18]:= Times @@ Dimensions[data]/9 Out[18]= 16