How can I change where a variable is placed within the field width using fprintf?

I am working with a function that specifies a field width of 20 characters for column labels.

for i=1:length(q.labels)

fprintf(fid, '%20s\t', q.labels{i});

end

The problem I am having, is that in the written file, the label is being printed to the last characters of the 20-character field width. So, for example, if my label is ‘DOG’, my column label has 17 blank spaces and then the word DOG. How can I fix this so that the label prints to the beginning of the field width?

Answer 1

[Yuan Li]

fprintf(fid,['%' num2str(length(q.labels{i})) 's\t'],q.labels{i});

change the code in the for loop will help you solve the problem.

Answer 2

[Stephen23]

By default the text will be right-justified within the field.

The fprintf documentation states that you can left-justify using the - character:

fprintf(fid, '%-20s\t', q.labels{i});
%              ^ this is all you need

Note that the loop is not required:

fprintf(fid, '%-20s\t', q.labels{:});