[GiNaC-devel] New in GiNaC: step function

[Vladimir Kisil]

>>>>> "CD" == Chris Dams <Chris.Dams at mi.infn.it> writes:
    CD> ignored. Furthermore step(0)=1/2. This, however, should not be
    CD> taken too seriously as there is also the automatic evaluation
    CD> step(x)^2 -> step(x). 

	For a bigger consistency I would prefer to have either step(0)=0 or
  step(0)=1. Such a small features which is easy to overlook sometimes
  takes hours to realise. 
  
  If three-values are really needed we may have another function
  sign(x)=1, x>0
  sign(x)=0, x=0
  sign(x)=-1, x<0
  
  with the property sign(x)^3 -> sign(x). The current step(x) is then
  (sign(x)+1)/2.

  Best wishes,
  Vladimir
-- 
Vladimir V. Kisil     email: kisilv at maths.leeds.ac.uk
--                      www: http://maths.leeds.ac.uk/~kisilv/