Writing code to calculate difference between 2 ones in logic matrix

Hi all, I'd like to write code to measure distance between two ones in logic matrix (1x24) attached below: I will be so grateful if someone help me. Best Regards

Answer 1

[per isakson]

A starting point

    num = [0,0,0,0,1,1,1,1,0,0,0,0,0,0,0,0,0,1,1,1,1,0,0,0];
    bol = logical( num );
    ix1 = find( bol );
    dix = ix1(2:end)-ix1(1:end-1) - 1;
    dix( dix >= 1 )

it returns

    ans =
         9
    >>

&nbsp

Answer to comment, which basically is the solution by Mohammad Abouali with a few comments.

num = [0,0,0,0,1,1,1,1,0,0,0,0,0,0,0,0,0,1,1,1,1,0,0,0,0,0,0,1,1,1,0,0,0,0,0]; 
dn1 = diff([0,num]);    % make sure the first value is zero
ix1 = find( dn1 == 1 ); % indicies of the "first ones"  
dix = diff( ix1 ) -1;   % distance between successive "first ones"

returns

dix =
    12     9

[Ali Noori]

Many thanks Sir, it is works correctly. I will be so grateful again if you help me with second attached file below:

[Mohammad Abouali]

A=[0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 0 1 1 1 0 0 0 0 0]
diff(find(diff([0 A])>0))-1

ans =

      12     9

Answer 2

[Image Analyst]

I see you tagged it as image processing. If you want an image processing method of doing it, it would be to use regionprops to measure the "Area" (length) of the runs of zeros.

% Example 1
num = [0,0,0,0,1,1,1,1,0,0,0,0,0,0,0,0,0,1,1,1,1,0,0,0];
% Trim off leading and trailing zeros
num = num(find(num==1, 1, 'first'):find(num==1, 1, 'last'));
% Measure the lengths of the stretches/runs of zeros.
measurements = regionprops(logical(~num), 'Area');
lengthOfZeroStretches = [measurements.Area]

% Example 2
num = [0,0,0,0,1,1,1,1,0,0,0,0,0,0,0,0,0,1,1,1,1,0,0,0,0,0,0,1,1,1,0,0,0,0,0]; 
% Trim off leading and trailing zeros
num = num(find(num==1, 1, 'first'):find(num==1, 1, 'last'));
% Measure the lengths of the stretches/runs of zeros.
measurements = regionprops(logical(~num), 'Area');
lengthOfZeroStretches = [measurements.Area]

In the command window:

lengthOfZeroStretches =
     9
lengthOfZeroStretches =
     9     6