Thread Subject: Cells :Remove empty and size(1,1)

Hi! I have a large cell array with entries similar:
a{1}=[1 2 3 4];
a{2}=[];
a{3}=[1];
a{4}=[1 2 3 4 5 6];

What is the most efficient way to remove the empty cells (a
{2}) and the cells with only 1 value (a{3})?

THanks,
S

"susan ":
<SNIP wants to remove the bad guys...

one of the many solutions

     a{1,1}=[1 2 3 4];
     a{2,1}=[];
     a{3,1}=[1];
     a{4,1}=[1 2 3 4 5 6];
     ix=cellfun(@numel,a);
     a(ix<=1)=[]

us

in the same line:

a(cellfun(@isempty,a))=[]

On Wed, 13 Feb 2008 14:07:13 -0500, Bruno Luong <b.luong@fogale.fr> wrot=
e:
> in the same line:
>
> a(cellfun(@isempty,a))=3D[]
>

That only removes empty cells. If you want to remove cells with <=3D1 =

element, use
a( cellfun(@(x)numel(x)<=3D1, a) ) =3D [];


--Arthur

"Arthur G" <gorramfreak+news@gmail.com> wrote in message
<op.t6g9ogca1g2ca1@arthurmbp.local>...

> That only removes empty cells. If you want to remove cells
with <=3D1 =
>

Oops you are right,I should read the question more carefully.

Bruno

"Arthur G":
<SNIP solution with a bad taste...

> use
> a( cellfun(@(x)numel(x)<=1, a) ) = [];

i suggest to NOT do this; rather use the first (us's)
approach as a one liner - i'll show you why:

% the data
     a{1}=[1 2 3 4];
     a{2}=[];
     a{3}=[1];
     a{4}=[1 2 3 4 5 6];
     b=a;
% ag
tic;
for i=1:10000
     a=b;
     a(cellfun(@(x) numel(x)<=1,a))=[];
end;
toc
% Elapsed time is 0.669293 seconds.
% us
tic;
for i=1:10000
     a=b;
     a(cellfun(@numel,a)<=1)=[];
end;
toc
% Elapsed time is 0.136211 seconds. % ~19%!!!!!

just a thought...
us
ps: i leave it up to you to figure out why this happens...