hi i have 1x36 cell,each cell contains 7x7 double, i need to divide each 7x7 equally into 4 halves and find max value in each halves,likewise for all 36 cells

help me with matlab code

[Alexandra Harkai]

How would you define equal halves of a 7*7 matrix? What does 'divide into 4 halves' mean?

[kaavya subramani]

like plus sign, 4 quadrants,if it is not divided equally either ceil or floor can be used.

[Alexandra Harkai]

Can you give an example?

[kaavya subramani]

for eg=[1 2 3 4 5;6 7 8 9 10;1 12 13 14 15;16 17 18 19 20] my fist part contains [1 2 3 6 7 8],2nd part=[4 5 9 10],3rd part=[11 12 13 16 17 18],4th=[14 15 19 20],i need to find max value of each part also

Answer 1

[Guillaume]

yourcellarray = arrayfun(@(~) randi(20, 7), 1:36, 'UniformOutput', false)  %demo data

cellfun(@(m) cellfun(@(quadrant) max(quadrant(:)), ...  max of a quadrant
                     mat2cell(m, ...                    convert matrix in cell into cell of 4 quadrant
                              [ceil(size(m, 1)/2), floor(size(m, 1)/2)], ...
                              [ceil(size(m, 2)/2), floor(size(m, 2)/2)])), ...
        yourcellarray, 'UniformOutput', false) %process each cell

edit: removed the 'UniformOutput', false from the inner cellfun since it's actually not needed. The output is thus a 1x36 cell array of 2x2 matrix instead of a 1x36 cell array of 2x2 cell arrays of scalars.

[kaavya subramani]

Thanks...........a lot sir........

Answer 2

[KSSV]

clc; clear all ;
A = cell(1,36) ;
for i = 1:36
    A{i} = rand(7) ;
end
% 
B = cell(1,36) ;
for i = 1:36
    A1 = NaN(8) ;
    A1(1:7,1:7) = A{i} ;
    % split to equal parts like +
    A2(:,:,1) = A1(1:4,1:4) ;
    A2(:,:,2) = A1(1:4,5:8) ;
    A2(:,:,3) = A1(5:8,1:4) ;
    A2(:,:,4) = A1(5:8,5:8) ;
    % get maximum 
    B{i} = max(A2,[],3) ;
end

[kaavya subramani]

Thanks a lot sir,but i didnt get max value as per your code,also plz mention where to apply my data, in your code

[KSSV]

For the random values max is as expected....A should be your data..

Answer 3

[Bhanushnkar Gedela]

how to split the 16*64 matrix into 4 16*16 matrices