# cf.CellMeasure

class `cf.``CellMeasure`(properties={}, attributes=None, data=None, source=None, copy=True)

  Bases: `cf.variable.Variable`

  A CF cell measure construct.

  A cell measure construct provides information that is needed about the size or shape of the cells and that depends on a subset of the domain axis constructs. Cell measure constructs have to be used when the size or shape of the cells cannot be deduced from the dimension or auxiliary coordinate constructs without special knowledge that a generic application cannot be expected to have. The cell measure construct consists of a numeric array of the metric data which spans a subset of the domain axis constructs, and properties to describe the data (in the same sense as for the field construct). The properties must contain a `measure` property, which indicates which metric of the space it supplies e.g. cell horizontal areas, and a units property consistent with the measure property e.g. square metres. It is assumed that the metric does not depend on axes of the domain which are not spanned by the array, along which the values are implicitly propagated. CF-netCDF cell measure variables correspond to cell measure constructs.

  Attributes

  Attribute | Type | Description
  --- | --- | ---
  `measure` | `str` | The spatial measure being represented, either `'area'` or `'volume'`.

  Initialization

  Parameters: | properties: `dict`, optional Initialize CF properties from the dictionary’s key/value pairs. attributes: `dict`, optional Provide attributes from the dictionary’s key/value pairs. data: `cf.Data`, optional Provide a data array. source: `cf.{+Variable}`, optional Take the attributes, CF properties and data array from the source {+variable}. Any attributes, CF properties or data array specified with other parameters are set after initialisation from the source {+variable}. copy: `bool`, optional If False then do not deep copy arguments prior to initialization. By default arguments are deep copied.

## CF properties

`add_offset` | The add_offset CF property.
`calendar` | The calendar CF property.
`comment` | The comment CF property.
`_FillValue` | The _FillValue CF property.
`history` | The history CF property.
`leap_month` | The leap_month CF property.
`leap_year` | The leap_year CF property.
`long_name` | The long_name CF property.
`missing_value` | The missing_value CF property.
`month_lengths` | The month_lengths CF property.
`scale_factor` | The scale_factor CF property.
`standard_name` | The standard_name CF property.
`units` | The units CF property.
`valid_max` | The valid_max CF property.
`valid_min` | The valid_min CF property.
`valid_range` | The valid_range CF property.

## Attributes

`array` | A numpy array deep copy of the data array.
`binary_mask` | A binary (0 and 1) missing data mask of the data array.
`data` | The `cf.Data` object containing the data array.
`dtarray` | An independent numpy array of date-time objects.
`dtype` | The `numpy` data type of the data array.
`hardmask` | Whether the mask is hard (True) or soft (False).
`isscalar` | True if the data array is scalar.
`mask` | The mask of the data array.
`ndim` | The number of dimensions in the data array.
`shape` | A tuple of the data array’s dimension sizes.
`size` | The number of elements in the data array.
`subspace` | Return a new variable whose data is subspaced.
`Units` | The `cf.Units` object containing the units of the data array.
`varray` | A numpy array view of the data array.

## Methods

`all` | Test whether all data array elements evaluate to True.
`allclose` | Returns True if two broadcastable cell measures have equal array values to within numerical tolerance.
`any` | Return True if any data array elements evaluate to True.
`asdatetime` | Convert the internal representation of data array elements to date-time objects.
`asreftime` | Convert the internal representation of data array elements to numeric reference times.
`attributes` | Inspect or change attributes which are not CF properties.
`chunk` | Partition the data array.
`ceil` | The ceiling of the data array.
`clip` | Limit the values in the data array.
`close` | Close all files referenced by the cell measure.
`copy` | Return a deep copy.
`cos` | Take the trigonometric cosine of the data array.
`datum` | Return an element of the data array as a standard Python scalar.
`delprop` | Delete a CF property.
`dump` | Return a string containing a full description of the cell measure.
`equals` | True if two cell measures are equal, False otherwise.
`exp` | The exponential of the data array.
`expand_dims` | Insert a size 1 axis into the data array.
`files` | Return the names of any files containing parts of the data array.
`fill_value` | Return the data array missing data value.
`flip` | Flip dimensions of the data array in place.
`floor` | Floor the data array.
`getprop` | Get a CF property.
`hasprop` | Return True if a CF property exists, otherise False.
`HDF_chunks` | Specify HDF5 chunks for the data array.
`identity` | Return the cell measure’s identity.
`insert_data` | Insert a new data array into the variable in place.
`inspect` | Inspect the object for debugging.
`log` | The logarithm of the data array.
`mask_invalid` | Mask the array where invalid values occur.
`match` | Determine whether or not a variable satisfies conditions.
`max` | The maximum of the data array.
`mean` | The unweighted mean the data array.
`min` | The minimum of the data array.
`mid_range` | The unweighted average of the maximum and minimum of the data array.
`name` | Return a name for the cell measure.
`override_calendar` | Override the calendar of date-time units.
`override_units` | Override the units.
`properties` | Inspect or change the CF properties.
`range` | The absolute difference between the maximum and minimum of the data array.
`rint` | Round data array.
`roll` | Roll the cell measure along an axis.
`sample_size` | The number of non-missing data elements in the data array.
`sd` | The unweighted sample standard deviation of the data array.
`select` | `cf.CellMeasure.select` has been deprecated.
`setprop` | Set a CF property.
`sin` | The trigonometric sine of the data array.
`squeeze` | Remove size 1 dimensions from the data array
`sum` | The sum of the data array.
`transpose` | Permute the dimensions of the data array.
`trunc` | Truncate the data array.
`unique` | The unique elements of the data array.
`var` | The unweighted sample variance of the data array.
`where` | Set data array elements depending on a condition.