Alphabetical Sorting (case insensitive)

23 views (last 30 days)
Aiden Chrisan
Aiden Chrisan on 19 Apr 2018
Answered: Suraj Mankulangara on 23 Apr 2018

Heyy everyone, Having small issue with my code, where i want to assort an array of words in alphabetical order (with specific case insensitive sorting). My code is;

A = ["help" ; "MATLAB" ; "anyTIME" ; "matrix" ; "alGEBra"];
[M,N]=size(A);
for i = 2:N
    char = A(i,:);
    j = i-1;
      A_j=A(j+1,:);
      A(n+1:i)=A_j(A_j>char);
      j=j-max(A_th);
      A(j+1,:) = char;
end
disp(A);

it assorts the words, but not correctly. I can successfully do this sorting with numbers no problem. And i can sort the words alphabetically with the output case sensitive(have a couple different codes but wont attach them coz i dont want to bore you lovely people). but getting the output as alphabetical AND case insensitive is proving much more problematic (NOTE: i know you could use the sort function, but i want to do it with this one for loop). Any help is much appreciated <3

  1 Comment
Stephen23
Stephen23 on 19 Apr 2018
Edited: Stephen23 on 19 Apr 2018
The first line
A = ["help" ; "MATLAB" ; "anyTIME" ; "matrix" ; "alGEBra"];
defines a 5x1 string array. Then you measure the size of that string array using
[M,N]=size(A);
So given that N==1, I don't see how this for loop will ever iterate even once:
for i = 2:N
Also, if A is really a string array, then char = A(i,:); is not a char vector but another string array.

Sign in to comment.

Answers (1)

Suraj Mankulangara
Suraj Mankulangara on 23 Apr 2018
Hello Aiden,
Here's a simple (and likely not very efficient) bubblesort implementation of case-insensitive string array sorting:
A = ["help" ; "MATLAB" ; "anyTIME" ; "matrix" ; "alGEBra"];
[M,N]=size(A);
for i = 1:M-1
for j = 1:M-1
curr = A(j);
next = A(j+1);
if upper(curr) > upper(next)
A(j) = next;
A(j+1) = curr;
end
end
end
disp(A);
I do not quite understand why you do not want to use the in-built MATLAB "sort" function to achieve this. There is no need to reinvent the wheel. Also, the in-built functions are likely to be much more efficient and optimized. You could do case-insensitive sorting using the "sort" function by converting all characters to uppercase, like this:
[~,idx]=sort(upper(A))
out=A(idx)

Categories

Find more on Shifting and Sorting Matrices in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!