Extract the column/ row numbers or adress

Hi,

I have 1 x 10000 matrix which got values of 0, 1 in it. Here, I would like to get the information on column numbers which got the value 1. Attached, here is th matrix. Please help me with this...

[Omid Saeidi]

find(c==1)

c is the name of column

[Turbulence Analysis]

Thanks, I works perfectly..

[dpb]

NB: Depending upon the next step(s), often one doesn't need to actually return the indices themselves but can simply use the logical addressing vector.

If so, may save a temporary variable plus the overhead of the find() operation itself.

Answer 1

[Adam Danz]

> I would like to get the information on column numbers which got the value 1

For logical row vectors or numeric row vectors containing 1|0,

colNum = find(c);

If the row vector contains values other than 0|1 and you want to find the 1s, follow Omid Saeidi's advice,

colNum = find(c==1);

If you're planning on indexing, follow dpb's advice and use logical indexing

logidx = logical(c);  % if c is numeric
% or 
logidx = c==1;        % if c contains values outside of 0|1

[Turbulence Analysis]

Thanks a lot for detailed explanation. Its working good...

Besides, I having an issue while running the for loop with intervals,

I am running the for loop with the intervals as shown below, here at the end of each sequence I need to save the average matrix for e.g.55 to 65, then that particular matrix needs to be cleared then continue with next seqeunce i.e. 125:1:145 and so on.. Is there a way to do this ???

for kk = [55:1:65 125:1:145 201:1:225]
    % my code
end

[Adam Danz]

I would define the sequences within a variable and loop through each sequence.

seq = {55:65;  125:145;  201:225};
for j = 1:numel(seq)
    for kk = seq{j}
        
        % your code
        
    end
end

[Turbulence Analysis]

Thanks.. It's perfect..