ComputerArithmetic`
ComputerArithmetic`

Ulp

Ulp[x]

gives the size of an ulp for numbers near x.

Details and Options

  • To use Ulp, you first need to load the Computer Arithmetic Package using Needs["ComputerArithmetic`"].
  • The difference between two consecutive machine numbers is called an ulp, which stands for "unit in the last place".
  • The size of an ulp varies depending on where you are in the set of machine numbers. Between 1 and 2 an ulp is equal to $MachineEpsilon, between 2 and 4 an ulp is equal to 2$MachineEpsilon, etc.