MathGroup Archive 2007

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

Search the Archive

Re: ListDimension function


On Jan 10, 2007, at 4:07 AM, carlos at colorado.edu wrote:

> Hi - I need a short function ListDimension that
> given a list returns its "brace dimensionality" =
> max number of brace levels to reach deepest entry.
> Examples
>
>    List         ListDimension
>    a+b                   0
>    {1,2,x*y}             1
>    {1,2,{3,0,1}}         2
>    {{},{},{}}            2
>    {{},{{1,2}},a}        3
>
> Built-in functions dont seem to be of help.
> Dimensions is restricted to matrix or tensor type of lists.
> Depth (minus 1) doesnt help as it is entry type dependent:
>
>    Depth[{1,2,3}] -> 2
>    Depth[{1,2,3+a}] -> 3
>    Depth[{1,2,3+a+Sqrt[x+y]}] -> 5
>
> For the above three, ListDimension=1.

Here is a newbie approach.

If your list is lst, then:

In[2]:=
Max[Length /@ Position[lst,
     List]]
Out[2]=
3

will work.  For a+b it gives minus Infinity if you can live with that.

János


  • Prev by Date: Re: Call-by-reference from inside a function
  • Next by Date: Re: Efficient Computation involving a Hypergeometric function...
  • Previous by thread: Re: ListDimension function
  • Next by thread: Re: ListDimension function