How to find the row and column for a value within a matrix [c] nearest or equal to 700.

Attempts so far.

for inputMat = [c];

[row,col] = find (c==700);

end

inputMat = [c];

[myRow, myCol] = find(inputMat (closest(700)));

numericalAns = [myRow myCol];

Answer 1

[John D'Errico]

Easy. And there would be many ways to do it.

c = rand(5,5)*1000

c = 5×5

954.2387 395.1216 623.5493 716.9854 244.7619 872.3532 774.9458 535.5974 226.3258 561.0368 336.4275 785.2196 738.6107 98.0277 66.3741 403.5059 623.4173 598.7175 232.5904 992.2769 692.0418 126.7045 426.2907 594.1339 735.1474

[~,ind] = min(abs(c(:) - 700))

ind = 5

[rowind,colind] = ind2sub(size(c),ind)

rowind = 5

colind = 1

So the closest element to 700 lives in row 5, column 1.

c(rowind,colind)

ans = 692.0418

[Alex Hinchcliffe]

Thanks John, nice example and explanation. This seems to work very well.

Answer 2

[Jan]

find(inputMat (closest(700)))

This is pure guessing. Notice that a command like closest(X) cannot even work in theory, because you provide one input only. So if this command exists, Matlab would ask: "closest to what?"

for inputMat = [c];

This is not the way Matlab's FOR loop works.

Guessing is no successful strategy for such a powerful tool as Matlab. Please read the GEtting Started chapters of the documentation and read Matlab's Onramp: https://www.mathworks.com/learn/tutorials/matlab-onramp.html

[value, index] = min(abs(c(:) - 700))
[row, col]     = find(c == c(index))    % [EDITED, Typo fixed]
% Replies multiple matchs, if there are some

[Alex Hinchcliffe]

Thanks for the reply, i couldnt seem to get a row and col value with this though. It came up with

row =

0×1 empty double column vector

col =

0×1 empty double column vector

I will have a read through the information in the link.

[Jan]

Yes, the code failed due to a typo. This is fixed now.