# cf.Coordinate.Z

`Coordinate.``Z`

  True if and only if the coordinates are for a CF Z axis.

  CF Z axis coordinates are for a vertical axis have one or more of the following:

  > - The `axis` property has the value `'Z'`
  > - Units of pressure (see `cf.Units.ispressure` for details), level, layer, or sigma_level
  > - The `positive` property has the value `'up'` or `'down'` (case insensitive)
  > - The `standard_name` property is one of `'atmosphere_ln_pressure_coordinate'`, `'atmosphere_sigma_coordinate'`, `'atmosphere_hybrid_sigma_pressure_coordinate'`, `'atmosphere_hybrid_height_coordinate'`, `'atmosphere_sleve_coordinate`’, `'ocean_sigma_coordinate'`, `'ocean_s_coordinate'`, `'ocean_s_coordinate_g1'`, `'ocean_s_coordinate_g2'`, `'ocean_sigma_z_coordinate'` or `'ocean_double_sigma_coordinate'`

  See also

  `ctype`, `T`, `X`, `Y`

  Examples: |

      >>> c.Units
      <CF Units: Pa>
      >>> c.Z
      True

      >>> c.Units.equivalent(cf.Units('K')) and c.positive == 'up'
      True
      >>> c.Z
      True

      >>> c.axis == 'Z' and c.Z
      True

      >>> c.Units
      <CF Units: sigma_level>
      >>> c.Z
      True

      >>> c.standard_name
      'ocean_sigma_coordinate'
      >>> c.Z
      True