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

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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});
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?

Accepted Answer

Yuan Li
Yuan Li on 21 Oct 2019
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.

More Answers (1)

Stephen23 on 21 Oct 2019
Edited: Stephen23 on 21 Oct 2019
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{:});


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