How do I round a float to a specified number of significant digits in Ruby?

Question

It would be nice to have an equivalent of R\'s signif function in Ruby.

For example:

>> (11.11).signif(1)
10
>> (22.22).signif(2)
22
>         


        

Answer 1

Use sprintf if you want to print trailing zeros

2.0.0-p353 :001 > sprintf "%.3f", 500
 => "500.000"
2.0.0-p353 :002 > sprintf "%.4f", 500
 => "500.0000"
2.0.0-p353 :003 >