How do I add commas to numbers using fprintf?

Hello,

How do I add commas to numbers using fprintf? My customer wants me to write out tables and have commas in the numbers to better read it. For instance, 123456789.0 would be written out as 123,456,789.0. Thanks.

Best regards,

Bill Rooker

Answer 1

[Stephen]

fprintf cannot do that, but you will find several FEX submissions that can create a string with commas as thousands separators:

https://www.mathworks.com/matlabcentral/fileexchange/52832-num2sepstr

https://www.mathworks.com/matlabcentral/fileexchange/41520-insert-commas-into-numbers

If you read the comments to those submissions you will also find several improvements to consider.

Answer 2

[Ted Shultz]

you can do this in two lines. from this page : A simple way is to add this two line function:

function numOut = addComma(numIn)
   jf=java.text.DecimalFormat; % comma for thousands, three decimal places
   numOut= char(jf.format(numIn)); % omit "char" if you want a string out
end

Hope that helps! --ted

[Roscoe Cook]

Worked great for me! Perhaps this should be the accepted answer. Thanks!

[Stargaet]

very good! thanks!

[Kouichi C. Nakamura]

Thanks! Extended it to 2d matrix.

function B = AddCommaArr(A)

B = strings(size(A));

for i = 1:size(A,1)
    for j = 1:size(A,2)
        
        B(i,j) = addComma(A(i,j));
    end
end

function numOut = addComma(numIn)
   jf=java.text.DecimalFormat; % comma for thousands, three decimal places
   numOut= char(jf.format(numIn)); % omit "char" if you want a string out
end

end

[Daven Gooden]

@Ted Shultz: Spot on! Very clean and easy to understand/use! Thank you very mutch!

Answer 3

[Jim Svensson]

I feel that in 2021 this functionality should be supported by sprintf/fprintf.

Answer 4

[Bill Rooker]

Thank you!