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

Some of the previous answers and comments have alluded to this solution but this is what worked for me:

# takes in a float value and returns another float value rounded to 
# given significant figures.    
def round_to_sig_figs(val, sig_figs)
  BigDecimal.new(val, sig_figs).to_f
end