In an assignment A(:) = B, the number of elements in A and B must be the same.

I have a problem in the line with <<<<<<<<<<<<<<<

TestID= fopen('Test_text_file.txt','r');
abstract_words= textscan(TestID , '%s');
fclose(TestID);
alphabet = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z' ...
    '(',')','.',',','/','-',' '].';
 num_words= length(abstract_words{1});
 Prob=zeros(length(alphabet),1);
 R= reshape(abstract_words{1},[1,num_words]);
 C2M= cell2mat(R);  
 for i= 1:length(alphabet)
     F= find(C2M == alphabet(i));
     Prob(i) = length(F);
     display(strcat(alphabet(i),' -->  ',num2str(Prob(i))));
 end
 space= num_words-1;
  Prob(33)=space;
Prob= Prob /sum(Prob);
figure;
stem(Prob);
[J,I] = sort(Prob, 'descend');                    %sort probabilities descending with indicating their indices
SA= alphabet(I);                                   %sorted alphabet
LengthOfAlphabet= i;
for i=1:LengthOfAlphabet
    Code(i)= ' ';
    index{i} = i;
end
while(length(Prob)> 2)
[~,Prob] = sort(Prob, 'descend');  
Smallest= Prob(length(Prob));
Before_smallest = Prob(length(Prob)-1);
Smallest_set = index{Smallest};
BS_set = index{Before_smallest};
Smallest_P = Prob(Smallest);
BF_P = Prob(Before_smallest);
Joined_set = {Smallest_set,BS_set};
SumProb= Smallest_P + BF_P ;
% Last =index(length(Prob));
% BL = index(length(Prob)-1);
index{Prob(length(Prob))} = ' ';
index{Prob(length(Prob)-1)} = ' ';
Prob (Prob(length(Prob):length(Prob)-1))= ' ';
index = [index Joined_set];
Prob  = Prob+SumProb;
for o=1:length(Smallest_set)
    Code(Smallest_set(o))= strcat('1',Code(Smallest_set(o)));
end
for o=1:length(BS_set)
    Code(BS_set(o))= strcat('0',Code(BS_set(o))); <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
end
% Prob=Prob-1;
end
Symbols=alphabet;
Code_Word=Code;

[Stephen23]

@Fatma Alsadani: today I formatted your code correctly for you (including removing all of those awkward blank lines). In future you can do it yourself: select the code text, click the {} Code button, and ensure that there is one empty trailing line.

PS: a much simpler way to define alphabet:

alphabet = ['a':'z','().,/- '].'

[Fatma Alsadani]

Okay Thank you :)

[Bob Thompson]

I would guess you're getting the error because '0' and Code(BS_set(o)) are not the same size. I would assume that Code(BS_set(o)) is a matrix, so matlab isn't going to like doing strcat() between a matrix and a string.

I would suggest confirming that all of your variables are the right class type, you can check with class(Code(BS_set(o))). If they appear correct try running the command in the command line, rather than in the script itself. This will tell you if there is an issue with the command and entered values, or something in the script itself.

Answer 1

[Guillaume]

I would have thought you'd get an error in the previous loop with your:

 Code(Smallest_set(o)) = strcat('1',Code(Smallest_set(o)));

Code(Smallest_set(o)) selects a given number (let's call it n) of elements from Code. You prepend that n number of elements with a '1', hence you now have something with n+1 elements. Trying to stuff these n+1 elements into the original n elements is never going to work and that is what the error message it telling you.

How to solve this, I do not know since I have no idea what it is you're trying to do.

[Fatma Alsadani]

I'm trying te replace an alphabet with a set of 1's and z's for each alphabet based on huffman theory