How can I use a variable for formatting?

Hi.

I have this line of code:

address = num2str(str2double(string(dec2bin(find(strcmp(dictionary,content(1:end-1)))))),'%04d');

It works, but I would like that the 4 is taken from a variable.

In particular, my variable is

numBits = ceil(log2(length(phrases)));

Is there a way to do so? Thanks

Answer 1

[Les Beckham]

You can also use %*d, like this

for k = 1:5
    fprintf('%*d\n', k, 2*k); % the first argument (k) is the field width, 2*k is the value to print 
end

2
 4
  6
   8
   10

Documentation is here

By the way, why are you converting to string and then to double and then back to a string?

[Star Strider]

I’d forgotten about the variable filed width as an optional argument.

+1

[Rosario Frontino]

Thanks for your answer, I'm still working on the code so I'll optimize that conversion.

I don't get how to implement your solution on my code since num2str has only two parameters (format being the second) and of course I can't use a third.

[Star Strider]

Use sprintf instead of num2str —

for k = 1:5
    sprintf('%*d', k, 2*k)
end

ans = '2'

ans = ' 4'

ans = '  6'

ans = '   8'

ans = '   10'

.

[Les Beckham]

You are welcome. @Star Strider is correct, sprintf is the right way to go.

If an answer in the forum solves your problem, it is considered gracious to accept it. If not please add a comment to request additional clarification. Thanks.

[Rosario Frontino]

Yeah it works by using sprintf. Thanks you both