Find the indices of elements within a submatrix of a larger matrix
2 views (last 30 days)
Show older comments
Say I have a matrix "B" of ones and zeros and I find a smaller submatrix (with a "range" or radius of 60 cells) within "B" using the following, where "xpos" and "ypos" are x and y coordinates within "B". As an example, if my "xpos" is 1000 and "ypos" is 1000, I form a 60 cell submatrix around this position and call it "B_sub"
subx = max(1,xpos-range):min(n1,xpos+range);
suby = max(1,ypos-range):min(n2,ypos+range);
B_sub = B(subx,suby); %This is the submatrix around matrix B
I would like to find all zeroes in the submatrix, and I do this by the following:
xidx=find(B(subx,suby)==0);
"xidx" gives me the linear indices of zeros within the submatrix "B_sub", but I want to know what the subscript indices of these elements are within the larger matrix "B". I have tried ismember and intersect, but do not get the output I need.
2 Comments
Adam
on 3 May 2019
Can't you just add max(1,xpos-range) to x and max(1,ypos-range) to y if you use the two output variant of the find function?
Answers (0)
See Also
Categories
Find more on Creating and Concatenating Matrices in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!