How can I transform a number to string with space using num2str?

What is the result of "num2str(1,'%2d')"? I think it should be " 1", but the results is "1". I mean there is no space before "1". Actually, the result of "num2str(1,'%02d')" is "01", and the result of "num2str(1,'%-2d')" is "1". And, the result of "sprintf('%2d',1)" is " 1".

How can I transform a number to string with space using num2str?

Answer 1

[Simon]

Hi!

Maybe this way?

num = [1000; 1001];
% numeric part
numpart = arrayfun(@(x) sprintf('%2d', mod(x,100)), num, 'UniformOutput', false);
% letter part
letterpart = char(mod(num,26*100)./100+65);
% concat everything
retsult = strcat(letterpart, numpart)

[Jung-Woo]

Thanks a lot! It will help.. ^^

Answer 2

[Walter Roberson]

Use sprintf instead of nu2str()

sprintf('%2d', 1)

[Jung-Woo]

If it is the single number, sprintf will be OK. But, what if it is an array? num2str([1;2],'%2d') is "1;2" and 2x1 char. num2str([1;11],'%2d') is " 1;11" and 2x2 char. sprintf('%2d\n',[1;11]) is " 1;11" and 1x6 char. The results of them are the same, but the dimension is different. As you see, if there is a 2-digit number in the array, there is space before the 1-digit number. But, if there is only 1-digit number in the array, there is no space.

[Simon]

Hi!

Please compare

   sprintf('%2d\n',[1;11])

and

   sprintf('%d\n',[1;11])

[Walter Roberson]

numt = num(:).';  %make sure it is row vector
rem100 = mod(numt, 100);
lead2600 = mod((numt - rem100) ./ 100, 26) + 65;
longstr = sprintf('%c%2d\n', [lead2600; rem100]);
strs = regexp(longstr, '\n', 'split');

Answer 3

[Jung-Woo]

Let me ask another way. Actually, I am trying to convert some numbers to alphabatical ID including alphabet and 2 digit numbers.

For example,

num = [1000; 1011];
cellstr([char(mod(num,26*100)./100+65),num2str(mod(num,100),'%2d')])
ans =
'K 0'
'K11'

That is what I want to have. But, if num = [1000; 1001], the 2-digit numbers become just 1-digit numbers like:

num = [1000; 1001];
cellstr([char(mod(num,26*100)./100+65),num2str(mod(num,100),'%2d')])
ans =
'K0'
'K1'

Here, my question is how I can fix the number of digit to 2. My expectation is:

ans =
'K 0'
'K 1'

[Walter Roberson]

You cannot use num2str() for this purpose. In situations in which every entry ends up with a leading blank, num2str() will strip off the leading blank.