ECHO: 0
ECHO: 1
ECHO: 2.2360679775
ECHO: 3.74165738677
ECHO: 5.47722557505
ECHO: undef
ECHO: nan
ECHO: inf
ECHO: inf
ECHO: undef
ECHO: undef
ECHO: undef
ECHO: undef
  WARNING: Incorrect arguments to norm()
ECHO: undef
  WARNING: Incorrect arguments to norm()
ECHO: undef
  WARNING: Incorrect arguments to norm()
ECHO: undef
  WARNING: Incorrect arguments to norm()
ECHO: undef
  WARNING: Incorrect arguments to norm()
ECHO: undef
ECHO: undef
ECHO: undef
ECHO: undef