How can code to present this following matrices
Question
I am doing my research. I have problem to make code to present this following matrices.
A(:,:,1)=[ 1 2 3 4;
3 2 1 4]
A(:,:,2)=[ 1 3 4 2;
4 2 1 3]
C(:,:,1)=[ 0 0 1 2;
1 1 1 0]
C(:,:,2)=[ 1 0 1 0;
0 1 1 1]
Matrices C is matrices that show how many zeros before value in matrice A.
And i have this following matrices to present value in matrices A.
value=1,
B(1)=[1 1 1;
1 1 1]
value=2,
B(2)=[2 2 2;
2 2 2]
value=3,
B(3)=[3 3 3;
4 4 4]
value=4,
B(4)=[4 4 4;
3 3 3]
So that I will get this following matrices by combining A and C.
Res(:,:,1)=[1 1 1 2 2 2 0 3 3 3 0 0 4 4 4;
1 1 1 2 2 2 0 4 4 4 0 0 3 3 3;
0 3 3 3 0 2 2 2 0 1 1 1 4 4 4;
0 4 4 4 0 2 2 2 0 1 1 1 3 3 3]
Res(:,:,2)=[0 1 1 1 3 3 3 0 4 4 4 2 2 2 0;
0 1 1 1 4 4 4 0 3 3 3 2 2 2 0;
4 4 4 0 2 2 2 0 1 1 1 0 3 3 3;
3 3 3 0 2 2 2 0 1 1 1 0 4 4 4]
I got this following from other forum.
CP = bsxfun(@minus, 3 , sum(C,2));
G = mat2cell(C,ones(size(C,1),1),ones(size(C,2),1),ones(size(C,3),1));
CP = mat2cell(CP,ones(size(CP,1),1),ones(size(CP,2),1),ones(size(CP,3),1));
D = B(A);
E = cellfun(@(x,n) [zeros(size(x,1),n) x], D, G,'UniformOutput',false);
for ii=1:depth;
E(:,end,ii) = cellfun(@(x,n) [x,zeros(size(x,1),n)],E(:,end,ii),CP(:,:,ii),...
'UniformOutput',false);
NewMatrice(:,:,ii)=cell2mat(E(:,:,ii));
end
What is your Opinion?
Solution
For starters, I don't understand how your matrix A
both holds the first A = [ 1 2 3 4; 3 2 1 4]
and A(1)
, A(2)
, A(3)
and A(4)
at the same time.
I suppose that you have the following instead:
A = [1, 2, 3, 4; 3, 2, 1, 4];
B(:, :, 1) = [1, 1, 1; 1, 1, 1];
B(:, :, 2) = [2, 2, 2; 2, 2, 2];
B(:, :, 3) = [3, 3, 3; 4, 4, 4];
B(:, :, 4) = [4, 4, 4; 3, 3, 3];
Assuming this, you can get your desired result in the following way:
Res = cell2mat(arrayfun(@(n)B(:, :, n), A, 'UniformOutput', false));
which yields:
Res =
1 1 1 2 2 2 3 3 3 4 4 4
1 1 1 2 2 2 4 4 4 3 3 3
3 3 3 2 2 2 1 1 1 4 4 4
4 4 4 2 2 2 1 1 1 3 3 3
EDIT #1:
Following the update to your question, if you have another matrix C = [0, 0, 1, 2; 1, 1, 1, 0]
that represents the number of leading zeros to insert before the B
matrices, you can get your desired result in the following way:
my_func = @(n)[zeros(size(B(:, :, A(n)), 1), C(n)), B(:, :, A(n))];
Res = cell2mat(arrayfun(my_func, reshape(1:numel(A), size(A)), 'Uniform', false))
this yields:
Res =
Columns 1 through 15
1 1 1 2 2 2 0 3 3 3 0 0 4 4 4
1 1 1 2 2 2 0 4 4 4 0 0 3 3 3
0 3 3 3 0 2 2 2 0 1 1 1 4 4 4
0 4 4 4 0 2 2 2 0 1 1 1 3 3 3
EDIT #2:
Following the second update to your question, if your A
and C
matrices are 3-dimensional, this adds a lot of complexity to the code. I find it easiest to use a for
loop and reduce the problem to 2-D, like so:
for k = 1:size(A, 3)
A2 = A(:, :, k);
C2 = C(:, :, k);
my_func = @(n)[zeros(size(B(:, :, A2(n)), 1), C2(n)), B(:, :, A2(n))];
Res(:,:,k) = cell2mat(arrayfun(my_func,reshape(1:numel(A2),size(A2)),'Un',0))
end
If you want different sizes for Res
in each iteration, I suggest you make Res
a cell array, i.e.:
Res{k} = cell2mat(arrayfun(my_func,reshape(1:numel(A2),size(A2)),'Un',0))
P.S.
Notice that for the second iteration you have C = [1, 0, 1, 0; 0, 1, 1, 1]
you'll get a problem, because the second row won't have the same amount of zeroes as the first. I believe you meant something like this: C = [1, 1, 1, 0; 0, 1, 1, 1]
.
EDIT #3:
Here's code to generate a random matrix C
, where each row sums up to a predefined integer K
(which is also chosen arbitrarily):
K = fix(size(A, 2) * (1 + rand)); %# Pick a random K
C = rand(size(A)); %# Generate a random C
C = ceil(C * K ./ repmat(sum(C, 2), 1, size(A, 2))) - 1; %# Normalize
C(:, end) = C(:, end) + K - sum(C, 2); %# Fix illegal rows