Replacing indexed row with string

Hi, I have a matrix that contains all the row numbers and I would like these row numbers to be replaced by the string 'a' in the empty vector test. For the row numbers not indexed, I would like them to be replaced with 'b'.

The code does not seem to allow replacement with a string. Do let me know how to solve this thanks!

test(find(lv1),:) = 'a'

Answer 1

[Mathieu NOE]

hello

see example below

hope it helps

test = (1:30);
test(3:15) = 0; % create some zeroes in the vector

%% main code %%
test = test(:); % makes test always vertical

tol = eps;
ind1 = find(abs(test) <= tol);  % zero elements 
ind2 = find(abs(test) > tol);   % non zero elements
test_str =num2str(test);    % convert numerical to string
[m,n] = size(test_str);

for ci = 1:length(ind1) % zero elements
    test_str(ind1(ci),:) = [blanks(n-1) 'a'];
end

for ci = 1:length(ind2)  % non zero elements
    test_str(ind2(ci),:) = [blanks(n-1) 'b'];
end