MATLAB: How to store [row,col]= find(X==a) results in a N*2 matrix ?!

find(x==a)

How can I store [row,col]= find(X==a) results in a N*2 matrix ?! I have a 100×100 matrix and I want to store the indices(i,j) of all elements from my 100×100 matrix they are equal 3 in another Nx2 matrix. I can extract indices with [row,col]= find(X==3) but I need the in a N*2 matrix.

Best Answer

Unless I’m missing something in your Question, I would create an (Nx2) matrix of the row and column indices as:

[row,col]= find(X==3);
Index_Mtx = [row col];

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MATLAB: Creating a n*2 array from a variable in workspace

Try this and then adapt as needed:

% Creating bounding box at any given x,y
grayImage = imread('moon.tif');
[rows, columns, numberOfColorChannels] = size(grayImage)
imshow(grayImage);
boxHalfWidth = 40; %
xy = boxHalfWidth + rand(10, 2) * (rows - 2 * boxHalfWidth);
for k = 1 : size(xy, 1)
	x = xy(k, 1);
	y = xy(k, 2);
	hold on
	plot(x, y, 'r+', 'MarkerSize', 25)
	boxXStart = x-boxHalfWidth;
	boxYStart = y-boxHalfWidth;
	boxWidth = 2 * boxHalfWidth;
	boxHeight = 2 * boxHalfWidth;
	rectangle('Position',[boxXStart boxYStart boxWidth boxHeight], 'EdgeColor', 'r')
end

Best Answer

Related Solutions

MATLAB: Filter out nonzero number in array of n*2 dimension.

MATLAB: Creating a n*2 array from a variable in workspace

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