MATLAB: How to arrange the values of the matrix according to index number

reorder

I have index number of matrix A =[1 3 5 6], B= [ 2 4]. The values corresponding to index number matrix A is A1=[3 4 -7 5; 2 5 10 -9; -11 56 9 -4; 6 -7 4 20] and the values corresponding to index number matrix B is B1=[13 4 -70 51; -1 95 12 -9].

I want to generate a matrix C with index number of A and B after sorting like C=[ 1 2 3 4 5 6] and the values of the matrix C1 will arrange according to the index numb of C.

How will be arranging the values of C1 from A1 and B1 according to the index number C? Please help on this

Best Answer

C_new = zeros(numel(A), numel([A, B]));
C_new(:, A) = A1;
C_new(:, B) = B1.'

Related Solutions

MATLAB: How to split a matrix into 2 matrixes then join it again

A =[2,6,3,1,7;9,4,2,6,3;7,1,4,5,3;7,2,5,6,3;4,2,5,3,5];
A1 = A(1:3, :);
A2 = A(4:5, :);
B = cat(1, A1, A2);  % Or [A1; A2]

These basic array operations are explained exhaustively in the Getting started chapters of the documentation.

MATLAB: How to modify a matrix to change the entries >=0 and multiply it by 5 AND to change the entries <0 and add 2 to those entries

Start with "If an entry in B is greater than or equal to zero": You can either run a loop over all elements of B or use "logical indexing":

% Linear indexing:
for k = 1:numel(B)
   if B(k) >= 0
     ...
   end
end

Or two indices for rows and columns:

for r = 1:size(B, 2)
  for c = 1:size(B, 1)
    if B(r, c) >= 0
       ...
    end
  end
end

Or "logical indexing":

index = (B >= 0);
disp(B(index))

Now try to use this to modify B. Use the mentioned terms to search in the documentation and in the internet.

Best Answer

Related Solutions

MATLAB: How to split a matrix into 2 matrixes then join it again

MATLAB: How to modify a matrix to change the entries >=0 and multiply it by 5 AND to change the entries <0 and add 2 to those entries

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