module Jacobian

def isEqual(a,b,zero=0.0,e=1.0e-8)

Determines the equality of two numbers by comparing to zero, or using the epsilon value 
def isEqual(a,b,zero=0.0,e=1.0e-8)
  aa = a.abs
  bb = b.abs
  if aa == zero &&  bb == zero then
    true
  else
    if ((a-b)/(aa+bb)).abs < e then
      true
    else
      false
    end
  end
end