3 plane to array vectorization

I have data in a matrix Atr

 >> whos Atr
  Name      Size                 Bytes  Class     Attributes

   Atr       7x3x2500            420000  double

I want to extract Atr(1,1,:) into a row vector Q. I tried like this

>>Q=Atr(1,1,:);
>> whos Q
Name      Size                Bytes  Class     Attributes

Q         1x1x2500            20000  double

But I need to store in a signle rwo vector . And also tried in this way

for i=1:2500
    Q(i)=Atr(1,1,i);
end

>> whos Q
  Name      Size                Bytes  Class     Attributes

    Q         1x1x2500            20000  double

But no help. How can I store in a single row vector ?

Answer 1

[Grzegorz Knor]

doc squeeze

Q=squeeze(Atr(1,1,:));

[Grzegorz Knor]

Another possibility:

Q = Atr (1,1,:);

Q = Q (:);

[Raviteja]

these are not working...

Above squeeze working....

Answer 2

[Andrei Bobrov]

Q = reshape(Atr(1,1,:),1,[])

variant for all matrix Atr

n = size(Atr);
Qarray = reshape(Atr,n(1)*n(2),[]);