in lz78 what is "??? Error using ==> cell.ismember at 28" and "Error in ==> lz78 at 19"

 datain=input('enter the string in single quote with symbol $ as End of string =');%input data
lda=length(datain);
dictionary=input('enter the dictionary in single quote(symbol used in string are to be included)=');%input dictionary
ldi=length(dictionary);
%for i=1:ldi
%dictnew(i)={dictionary(i)};
%end
dictnew(1)=datain(1);
s=dictnew(1);
i=1;
j=1;
k=1;
while datain(i)~= '$'
c=datain(i);
    if c~='$'
           check=ismember(dictnew,c);
           if(check==0)
                      if datain(i)=='$'
                      break
                      end
              dictnew(j+ldi)=datain(i);
               i=i+1;
               j=j+1;
           else
           s=datain(i+1);
           cat=strcat(c,s);
           check=ismember(dictnew,cat);
           if(check==0) 
                      if datain(i+1)=='$'
                      break
                      end
              dictnew(j+ldi)={cat};     
              i=i+2;
              j=j+1;
           else
            s=datain(i+2);
            cat=strcat(cat,s);
                      if datain(i+2)=='$'
                      break
                      end
             dictnew(j+ldi)={cat};
             i=i+3;
             j=j+1;
           end
        end
    end
end

Answer 1

[Walter Roberson]

We would need your input to reproduce those problems.

When I test with some strings of my own, I see that you have two places where you have

dictnew(j+ldi)={cat};

but you initialize dictnew as a single character (the first character of an input), and you cannot store a cell array into a character array.

You have other places where you have

dictnew(j+ldi)=datain(i);

so sometimes you store characters and other times you try to store cells.

Question: Why are you not using the 's' option of input ?

[manish yadav]

input string is 'abcdabcadbach$'

[Walter Roberson]

When I use that input with your code, I get

Conversion to char from cell is not possible.

Error in answers247495 (line 41)
             dictnew(j+ldi)={cat};

However, it is easy to show that the code you posted is not the same as the code you are having the problem with: the line shown as having a problem is at line 16 in what you posted, not at line 19.