how to find max of 1000 values which are rows,i wrote a code it showed just one value and index that is not the max

filename='realtimevalues.xlsx';
num=xlsread(filename);
y=filename(1,:);

[val idx]=max(y(:))

Answer 1

[Image Analyst]

num is a 2D array of numbers, or it may be depending on how your data area arranged in the workbook. y is the first character of filename, which is 'r'. I think you want

y = num(1, :); % Extract first row only.

[Titus Edelhofer]

Hmm, in the original post it's

y = filename(1,:)

?

y=num(:)

or

y=num(1,:)

both should give reasonable results, depending of what is searched for ...

[shina mokhtari]

it is the signal values

Answer 2

[Titus Edelhofer]

Hi Shina,

what exactly is the question: you think val is not the maximum of y? I don't see how this can happen ... Or are you interested in all indices where y is taking it's maximum? In this case you could do something like

idx = find(y(:)==max(y(:)));

Note though, that this is sensitive to floating point accuracy, so if you have

y = [1  1.0000000001 1]

this would find only idx=2.

Titus

[shina mokhtari]

you know i think the problem is i have 1000 values,and it show the wrong value and also index,for example when i write this code it show value 120 and index 16 wich is not true