read binary text from a file and add zeros to it

Please. I need to read binary text from a file and if it is not a multiple of a certain number, add zeros to te until it becomes a multiple of it,iam do tracing to my code and i discover that the statment a=......... in while loop donot change its value based on the new text,it remain on the first text.

text = fileread('text1.txt');                   
        n=input('enter the length of segment: ');
        a=mod(length(text),n);
            if a~=0
              
              
            while a~=0
                text=string(text)+"0";
                   a=mod(length(text),n);
            end
            end

Answer 1

[Image Analyst]

You forgot to attach the file!

If the text is binary like 0s and 1s, maybe try this

b = logical(readmatrix('text1.txt'));
% Make the vector 500000 elements long by padding zeros.
b(5000000) = false;

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Answer 2

[Walter Roberson]

if a~=0
  text = [text, repmat('0',1,n-a)];
end

Your bug is that you are converting text to string() array, but length() of a string array is the number of strings in the array, not the number of characters in the entry. See also strlength()

[Hadeel]

thank you so much for your answer.

Answer 3

[dpb]

What's the form of the file -- just a string of 0s and 1s? if so then it would be simply something like

text = fileread('text1.txt');                   
N=input('enter the length of segment: ');
text=strcat(text,'0',repmat(1,N-strlength(text)));

if N > strlength(text), thanee it will add enough '0' to make up N overall; repmat will silengly do nothing if the repeat count is <=0 so you don't need any other logic outside; it's all handled internally ("magic happens").

fileread returns a char() vector to begin with so there's no conversion required there, either.

[Walter Roberson]

'0' should be inside repmat

[Walter Roberson]

User wants output to be a multiple of N long rather than padding <N to N and leaving >N unchanged

[Hadeel]

thanks for your answer.the matters became ok