Index in position 1 is invalid.

Good day,

I have made the following Script to sotre the coordinates of centroid of laser beam from images

directory = 'C:\Users\anask\Desktop\test\';
Coordination = zeros(7,3);
files = dir([directory '/*.jpg']);
[~,index] = sortrows({files.date}.'); files = files(index); clear index;
for x = 1: numel(files)
    A= imread([directory '/' files(x).name]);
    %Convert the image ino binary image
    Ibw = im2bw(A);
    %Fill image regions and holes
    Ibw = imfill(Ibw,'holes');
    Ilabel = bwlabel(Ibw);
    %finding the centroid
    stat = regionprops(Ibw,'Area','Centroid');
    %Creating new array that have Area, X-coordinate, Y-coordinate

    area = cat(1,stat.Area);
    Coor = cat(1,stat.Centroid);
    
    %Combaining the results in one Array
    Array = cat(2,area,Coor);
    
    %Adding header
    %header = {'Area','x','y'};
    %Array = [header; num2cell(Array)];
   
   
   %Finding the maximum value
    maximum = max(max(Array(:,1)));
    [x,y]=find(Array==maximum);    
    
    
    %Apped the line of the maximum value in a new array
    if ~isempty(Coordination)
        Coordination(i,1:2) = Array(x,2:3);
    end
    
    clear stat
    clc

end

And I am keep getting the following error

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Index in position 1 is invalid. Array indices must be positive integers or logical values.

Error in Test (line 34)

Coordination(i,1:2) = Array(x,2:3);

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Can someone help me please to fix this issue, I want to store the coordinates in the coordinate array. The coordinate are derived from the row of the maximum area in 'Array' array.

Many thanks in advanced

Answer 1

[G A]

i as an index is not defined in your code, Matlab considers it as 1i by default

[ennes mulla]

so how can I define it here?

[G A]

I you have in Array several values equal to maximum, then perhaps (I replaced i by ii):

if any(x)
    for jj=0:length(x)-1
        Coordination(ii+jj,1:2) = Array(x,2:3);
    end
end
ii = ii + 1;

Also, because Coordination = zeros(7,3); at the beginning of the code, there is no need to do check by if ~isempty(Coordination);

[ennes mulla]

Great! Thanks A lot!

I have also added the following line before 'end' of the for loop and it helped too

i = i+1,

But your helped me too. Thank you!

[G A]

Avoid using i or j as indices. Also, my code above is still not correct, but if you have only one value in Array which is equal to maximum, your ii = ii + 1; at the end of the loop with ii = 1; before the loop will do the job.