Converting binary characters into a char - Error!

Hey, I have to convert a binary character into a char and I keep ending with an error.

This is not the entire code where I am trying to find the error in a message.

  %% Converting the binary stream into character string
   k= 4;

   n = 7;
   stream_n = reshape(msg_error_checked',n,[])';
   info_stream = stream_n(:,1:k);
   msg_stream = reshape(info_stream',1,[]);
  
   % question = bit2char(msg_stream) 
   % I tried using bit2char too but it doesn't work.  
   
   question = '' ;
   bin = msg_stream(1:7:length(msg_stream)-8);
   question = strcat( question,char(bi2de(bin,'left-msb')));

Error I get:

This is just a part from my entire code. I can post the entire code if necessary.

Thank you in advance.

[Aravind chockaiaah KANNAN]

very good question but i am unable to solve this....

Answer 1

[Walter Roberson]

You have 8 bits per character, not 7 bits per character. 255 characters of 8 bits each = 2040 bits.

[Aravind chockaiaah KANNAN]

what shoud he change here?

[Sanjay Ravichandran]

As I already stated, this is just a part of my code and n should be 7 to get the output.

I just want to know if there is anyway this could work.

[Walter Roberson]

n = 8;
stream_n = reshape(msg_error_checked',n,[])';
info_stream = stream_n(:,1:k);

question = dec2bin(char(info_stream.' + '0'));

[Walter Roberson]

How many characters are you expecting?

Why did you use 7 bits per character instead of 8?

[Sanjay Ravichandran]

I can't determine the number of characters, but at the end after coding it right. I am supposed to get a sentence like 'Welcome to Matlab'. (or maybe something else).

You can check this link for the codes:

https://www.mathworks.com/matlabcentral/answers/531408-converting-binary-to-string.

I am supposed to use 4 parity matrices among which one has the sentence.

With k being the identity matrix.

I had to eliminate the following values for k and n

1) 2 and 5

2) 3 and 6

3) 4 and 8

as I didn't get any sentence from them.

But when I use k as 4 and n as 7, I should be getting the output as its the last one left.

But, when I use the same code, it shows an error which I posted in the question section.