Index location in matrices

Hello,

I am trying to find the column in which the top row of my matric c reahes 0.7 and its corresponding position in matrix h. I don't need all the values after it reaches 0.7, just the column it first reaches it.

Please could someone help me.

Thank you.

Answer 1

[Image Analyst]

Try this:

columnIndex = find(c(1, :) >= 0.7, 1, 'first') % For matrix c
columnIndex = find(h(1, :) >= 0.7, 1, 'first') % For matrix h

[Sam Robinson]

This has worked to get my value in the c matrix, thank you.

But for the h matrix how can I write my code to dispaly the value in the column number from my matrix c?

For example, if its column 123 in matrix c (this value depends on my inputs) how can I get it to display the value for that position in h.

[Image Analyst]

columnIndex = find(c(1, :) >= 0.7, 1, 'first') % For matrix c
hValue = h(1, columnIndex) % Get h value at row 1, and in the same column as we found for c.

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[Sam Robinson]

How do I make this if 0.7 doesnt show in the top row of my c matrix? how do I get it to search each row at a time and tell me the row and column that it first appears in?

Appreciate your help

[Image Analyst]

Use a for loop

[rows, columns] = size(c)
columnIndexes = zeros(rows, 1); % Preallocate a column for every row in the matrix.
hValues = zeros(rows, 1); % Preallocate a column for every row in the matrix.
for row = 1 : rows
    location = find(c(1, :) >= 0.7, 1, 'first') % For matrix c
    if ~isempty(location)
        columnIndex(row) = location; % For matrix c
        hValue(row) = h(row, location) % Get h value at row 1, and in the same column as we found for c.
    end
end
% If any row did not have any value over 0.7, 
% then columnIndex for that row will be zero.