I'm working on a Matlab program that creates 2 n*n matrices, where n and each of the terms of the matrix (these will just be 0 or 1) are keyboard input values. The idea is that at the end the positions i,j in which the terms of the matrix are 1 are printed.
For example, if the inputs of matrix A are:
array = [];
array2 = [];
arrayb = [];
arrayb2 = [];
for m = 1: n
for n = 1: n
if A(m,n)==1;
array = [array, m];
array2 = [array2, n];
end
if B(m,n)==1;
arrayb = [arrayb, m];
arrayb2 = [arrayb2, n];
end
end
end
fprintf(array,array2)
The output should be
(1,1) = 1
(1,2) = 1
(2,1) = 0
(2,2) = 1
I have only been able to extract each of the term indices separately
{(1,1) ,(1,2), (2,2)}
CodePudding user response:
You can use find()
to find all non-zero values. use ~A
to reverse the booleanness and find the zeros afterwards. Then concatenate everything and use fprintf()
to print.
A = rand(3)>0.5; % Random sample data
[row, col, val] = find(A); % Find 1s
labels = [row.';col.';val.']; % concatenate for printing
fprintf('(%d, %d) = %d\n',labels) % print
[row, col, val] = find(~A); % Find 0s
val(:) = 0; % We know it should be 0
labels = [row.';col.';val.']; % concatenate for printing
fprintf('(%d, %d) = %d\n',labels) % print
% Output
A =
1 1 1
1 1 1
0 0 1
(1, 1) = 1
(2, 1) = 1
(1, 2) = 1
(2, 2) = 1
(1, 3) = 1
(2, 3) = 1
(3, 3) = 1
(3, 1) = 0
(3, 2) = 0
Or, in case you simply want to print all values with their indices, we can utilise meshgrid()
to quickly assemble the indices and then again unravel and concatenate before printing:
A = rand(3); % Random sample data
[col, row] = meshgrid(1:size(A,2), 1:size(A,1));
labels = [row(:).';col(:).';A(:).']; % concatenate for printing
% Change the printing spec for the value to something relevant
fprintf('(%d, %d) = %0.4f\n',labels) % print
A =
0.8147 0.9134 0.2785
0.9058 0.6324 0.5469
0.1270 0.0975 0.9575
(1, 1) = 0.8147
(2, 1) = 0.9058
(3, 1) = 0.1270
(1, 2) = 0.9134
(2, 2) = 0.6324
(3, 2) = 0.0975
(1, 3) = 0.2785
(2, 3) = 0.5469
(3, 3) = 0.9575