MATLAB: Boolean Vector Length Calculation

diff()vector length boolean

Hi all,

I have a vector consisting of booleans, either 1 or 0. Such as {0 0 0 0 1 1 1 0 0 0 0 0 1 1 0 0 0 0}. 1 values by itself cannot be in between of 0s. The same rule is valid also for 0s. I need the length of 1s separately. In other words, I do not want to know the length of all 1s. Instead, what I look for is the length of each 1s accumulated inside the vector independently. How can I find the length of 1s via matlab?

Thank you in advence.

Best Answer

The vector 'oneCounts' is a list of consecutive 1 counts. It's empty if there are no 1s.

tf = [0 0 0 0 0 1 1 1 0 0 0 0 0 1 1 0 0 0 0 1 1 1 0 0 1 1 1 1]; 
df = diff([0, tf, 0]);   %if tf is a column: diff([0;tf;0])
oneCounts = find(df == -1) - find(df == 1)
oneCounts =
     3     2     3     4

Related Solutions

MATLAB: What does “put a vector of ones in the 2nd row and a vector of ones in the 5th column” mean when I have a 10×10 matrix of zeros

>> A=zeros(10,10)
A(2,:)=1
A(:,5)=1
A =
    Columns 1 through 8
       0     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     0
    Columns 9 through 10
       0     0
       0     0
       0     0
       0     0
       0     0
       0     0
       0     0
       0     0
       0     0
       0     0
A =
    Columns 1 through 8
       0     0     0     0     0     0     0     0
       1     1     1     1     1     1     1     1
       0     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     0
       0     0     0     0     0     0     0     0
    Columns 9 through 10
       0     0
       1     1
       0     0
       0     0
       0     0
       0     0
       0     0
       0     0
       0     0
       0     0
A =
    Columns 1 through 8
       0     0     0     0     1     0     0     0
       1     1     1     1     1     1     1     1
       0     0     0     0     1     0     0     0
       0     0     0     0     1     0     0     0
       0     0     0     0     1     0     0     0
       0     0     0     0     1     0     0     0
       0     0     0     0     1     0     0     0
       0     0     0     0     1     0     0     0
       0     0     0     0     1     0     0     0
       0     0     0     0     1     0     0     0
    Columns 9 through 10
       0     0
       1     1
       0     0
       0     0
       0     0
       0     0
       0     0
       0     0
       0     0
       0     0
>>

zeros(10,10) which is the same as zeros(10) creates 10 by 10 matrix with zeros and with the above code ones are filled in 2nd row and in 5th column.

MATLAB: How to use an if else statement to choose one specific variable

X = tf2(tf==1);
Y = tf2(tf==0);

Best Answer

Related Solutions

MATLAB: What does “put a vector of ones in the 2nd row and a vector of ones in the 5th column” mean when I have a 10×10 matrix of zeros

MATLAB: How to use an if else statement to choose one specific variable

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