routine round

Documentation for routine round, assembled from the following types:

class Cool

From Cool

(Cool) routine round

Defined as:

multi sub round(Numeric(Cool))
multi method round(Cool:D: $unit = 1)

Coerces the invocant (or in sub form, its argument) to Numeric, and rounds it to the unit of $unit. If $unit is 1, rounds to the nearest integer.

say 1.7.round;          # OUTPUT: «2␤» 
say 1.07.round(0.1);    # OUTPUT: «1.1␤» 
say 21.round(10);       # OUTPUT: «20␤» 

Always rounds up if the number is at mid-point:

say (−.5 ).round;       # OUTPUT: «0␤» 
say ( .5 ).round;       # OUTPUT: «1␤» 
say (−.55).round(.1);   # OUTPUT: «-0.5␤» 
say ( .55).round(.1);   # OUTPUT: «0.6␤» 

role Real

From Real

(Real) method round

method round(Real:D: $scale = 1)

Rounds the number to scale $scale. If $scale is 1, rounds to an integer. If scale is 0.1, rounds to one digit after the comma etc.

class Complex

From Complex

(Complex) method round

Defined as:

multi method round(Complex:D: --> Complex:D)
multi method round(Complex:D: Real() $scale --> Complex:D)

With no arguments, rounds both the real and imaginary parts to the nearest integer and returns a new Complex number. If $scale is given, rounds both parts of the invocant to the nearest multiple of $scale. Uses the same algorithm as Real.round on each part of the number.

say (1.2-3.8i).round;           # OUTPUT: «1-4i␤» 
say (1.256-3.875i).round(0.1);  # OUTPUT: «1.3-3.9i␤»