Could you give me an advice about my error?

I am trying to put the data into cell space through serial communication.... I have 2 computer. One computer give another computer serial data. I added following code.

    Computer 1.
    s=serial('COM7')
    fopen(s)
    while(1)
    fwrite(s,[242 1 2 1 2 1 1 246])
    end

    Computer 2.
    s=serial('COM8')
    fopen(s)
    a=fread(s,50)
    j=0;
    data=cell(1,20);
    ch=1;
    for i=1:1:49
       ch=a(i)
          if(ch==242)
              data(1)=ch;
              j=1;
          elseif(ch==246)
              data(j)=ch;
              break
          else
              data(j)=ch;
              j=j+1;
          end
    end
    }  

Above code is to get the data through seial but I have problem in here.
Error message is "Conversion to cell from double is not possible.
How can I change my code to eliminate error...
I don't know which part is wrong..
Please help me. Thank you for reading.

Answer 1

[Walter Roberson]

Not data(1)=ch; but data{1}=ch; if you are going to use data as a cell array.

Are you sure you want to assign to position #1 of data and not to position #j ?

I do not at the moment see any reason why you would not use a character or numeric array instead of a cell array, though.

Answer 2

[Haksun Lee]

Thank you for your answer.. As you say, I'd like to use a character or numeric array instead of a cell array.

Which command can I use in order to numeric array?

I always appreciate your concern..

[Walter Roberson]

data = zeros(1,49);

or

data = blanks(49);