reshape a matrix in a special manner

Hi!

how could i make this matrix reschaping:

    % A=[A(:,1) A(:,2) A(:,3).....A(:,130)]
TO 
C1= mean([A(:,1)....A(:,10)],2)
C2=mean([A(:,11)........A(:,20)],2)
C3=mean([A(:,21)........A(:,30)],2)

C=[C1 C2 C3..........C13]

Thank you

Answer 1

[Pedro Villena]

 A = rand(100,130);
 step = 10;

 C = cell2mat(arrayfun(@(i,j) mean(A(:,i:j),2),...
     1:step:length(A)-step, 1+step:step:length(A),'un',0))

Answer 2

[José-Luis]

Faster:

 a = rand(100,130);
 [m n] = size(a);
 a = reshape(a,m,10,n/10); %Provided n is divisible by 10
 your_mat = squeeze(mean(a,2));

One liner of the above:

 your_mat = squeeze(mean(reshape(a,size(a,1),10,size(a,2)/10),2));

Answer 3

[Matt J]

Using the function below

 downsampn(A,[size(A,1),10]);  

function M=downsampn(M,bindims)
%DOWNSAMPN - simple tool for downsampling n-dimensional nonsparse arrays
%
%  M=downsampn(M,bindims)
%
%in:
%
% M: an array
% bindims: a vector of integer binning dimensions
%
%out:
%
% M: the downsized array

nn=length(bindims);

[sz{1:nn}]=size(M); %M is the original array
sz=[sz{:}];

newdims=sz./bindims;

args=num2cell([bindims;newdims]);

M=reshape(M,args{:});

for ii=1:nn

   M=mean(M,2*ii-1);

end

M=reshape(M,newdims);

Answer 4

[Matt J]

 m=mean(reshape(A,[],10,13),2);

 reshape(m,[],13);