Bases: object
An N-dimensional data array with units and masked values.
Indexing
A data array is indexable in a similar way to numpy array
>>> d.shape
(12, 19, 73, 96)
>>> d[...].shape
(12, 19, 73, 96)
>>> d[slice(0, 12), 10:0:-2, :, :].shape
(12, 5, 73, 96)
There are two important extensions to the numpy indexing functionality:
Size 1 dimensions are never removed.
An integer index i takes the i-th element but does not reduce the rank of the output array by one:
>>> d.shape
(12, 19, 73, 96)
>>> d[0, ...].shape
(1, 19, 73, 96)
>>> d[:, 3, slice(10, 0, -2), 95].shape
(12, 1, 5, 1)
When advanced indexing is used on more than one dimension, the advanced indices work independently.
When more than one dimension’s slice is a 1-d boolean sequence or 1-d sequence of integers, then these indices work independently along each dimension (similar to the way vector subscripts work in Fortran), rather than by their elements:
>>> d.shape
(12, 19, 73, 96)
>>> d[0, :, [0,1], [0,1,2]].shape
(1, 19, 2, 3)
Miscellaneous
Data objects are picklable.
Data objects are hashable, but note that, since Data objects are mutable, their hash values may change if created at different times.
Initialization
| Parameters : |
|
|---|
Examples
>>> d = cf.Data(5)
>>> d = cf.Data([1,2,3], units='K')
>>> import numpy
>>> d = cf.Data(numpy.arange(10).reshape(2,5), units=cf.Units('m/s'), fill_value=-999)
>>> d = cf.Data(tuple('fly'))
| array | A numpy array copy the data array. |
| data | The data array object as an object identity. |
| dtype | The numpy data type of the data array. |
| hardmask | Whether the mask is hard (True) or soft (False). |
| ismasked | True if the data array has any masked values. |
| isscalar | True if the data array is a 0-d scalar array. |
| mask | The boolean missing data mask of the data array. |
| ndim | Number of dimensions in the data array. |
| shape | Tuple of the data array’s dimension sizes. |
| size | Number of elements in the data array. |
| Units | The Units object containing the units of the data array. |
| unsafe_array | A numpy array of the data array. |
| varray | A numpy array view the data array. |
Partition matrix attributes
| pmdimensions | |
| pmndim | Number of dimensions in the partition matrix. |
| pmshape | Tuple of the partition matrix’s dimension sizes. |
| pmsize | Number of partitions in the partition matrix. |
| add_partitions | Add partition boundaries. |
| all | Test whether all data array elements evaluate to True. |
| all_axis_names | Return a set of all the dimension names in use by the data array. |
| any | Test whether any data array elements evaluate to True. |
| asdatetime | Change the internal representation of data array elements from numeric reference times to datatime-like objects. |
| asreftime | Change the internal representation of data array elements from datatime-like objects to numeric reference times. |
| binary_mask | Return a binary missing data mask of the data array. |
| change_axis_names | Change the axis names. |
| chunk | Partition the data array |
| clip | Clip (limit) the values in the data array in place. |
| close | Close all files referenced by the data array. |
| conform_args | Return a dictionary of arguments for the cf.Partition.dataarray |
| copy | Return a deep copy. |
| cos | Take the trigonometric cosine of the data array in place. |
| datum | Return an element of the data array as a standard Python scalar. |
| dump | Return a string containing a full description of the instance. |
| dumpd | Serialize the data array as a dictionary following loosely the CFA |
| equals | True if two data arrays are logically equal, False otherwise. |
| equivalent | True if and only if two data arrays are logically equivalent. |
| expand_dims | Expand the shape of the data array in place. |
| expand_partition_dims | Expand the shape of the partition matrix in place. |
| flat | Return a flat iterator over elements of the data array. |
| flip | Flip (reverse the direction) axes of the data array in place. |
| func | Apply an element-wise array operation to the data array in place. |
| loadd | Deserialize the dictionary, updating the master data array in place. |
| ndindex | Return an iterator over the N-dimensional indices of the data array. |
| new_axis_identifier | Return an axis name not being used by the data array. |
| override_calendar | Override the data array units in place. |
| override_directions | Override the data array directions in place. |
| override_units | Override the data array units in place. |
| partition_boundaries | Return the partition boundaries for each partition matrix dimension. |
| save_to_disk | Return True if the master array is large enough to be saved to disk. |
| setdata | Set data array elements depending on a condition. |
| sin | Take the trigonometric sine of the data array in place. |
| squeeze | Remove size 1 axes from the data array in place. |
| tan | Take the trigonometric tangent of the data array in place. |
| to_disk | Store the data array on disk in place. |
| to_memory | Store each partition’s data in memory in place if the master array is smaller than the chunk size. |
| transpose | Permute the dimensions of the data array in place. |
Arithmetic, bitwise and comparison operations are defined as element-wise data array operations which yield a new cf.Data object or, for augmented assignments, modify the data array in-place.
Comparison operators
| __lt__ | The rich comparison operator < |
| __le__ | The rich comparison operator <= |
| __eq__ | The rich comparison operator == |
| __ne__ | The rich comparison operator != |
| __gt__ | The rich comparison operator > |
| __ge__ | The rich comparison operator >= |
Truth value of an array
| __nonzero__ | Truth value testing and the built-in operation bool |
Binary arithmetic operators
| __add__ | The binary arithmetic operation + |
| __sub__ | The binary arithmetic operation - |
| __mul__ | The binary arithmetic operation * |
| __div__ | The binary arithmetic operation / |
| __truediv__ | The binary arithmetic operation / (true division) |
| __floordiv__ | The binary arithmetic operation // |
| __pow__ | The binary arithmetic operations ** and pow |
Binary arithmetic operators with reflected (swapped) operands
| __radd__ | The binary arithmetic operation + with reflected operands |
| __rsub__ | The binary arithmetic operation - with reflected operands |
| __rmul__ | The binary arithmetic operation * with reflected operands |
| __rdiv__ | The binary arithmetic operation / with reflected operands |
| __rtruediv__ | The binary arithmetic operation / (true division) with reflected |
| __rfloordiv__ | The binary arithmetic operation // with reflected operands |
| __rpow__ | The binary arithmetic operations ** and pow with reflected |
Augmented arithmetic assignments
| __iadd__ | The augmented arithmetic assignment += |
| __isub__ | The augmented arithmetic assignment -= |
| __imul__ | The augmented arithmetic assignment *= |
| __idiv__ | The augmented arithmetic assignment /= |
| __itruediv__ | The augmented arithmetic assignment /= (true division) |
| __ifloordiv__ | The augmented arithmetic assignment //= |
| __ipow__ | The augmented arithmetic assignment **= |
Unary arithmetic operators
| __neg__ | The unary arithmetic operation - |
| __pos__ | The unary arithmetic operation + |
| __abs__ | The unary arithmetic operation abs |
Binary bitwise operators
| __and__ | The binary bitwise operation & |
| __or__ | The binary bitwise operation | |
| __xor__ | The binary bitwise operation ^ |
| __lshift__ | The binary bitwise operation << |
| __rshift__ | The binary bitwise operation >> |
Binary bitwise operators with reflected (swapped) operands
| __rand__ | The binary bitwise operation & with reflected operands |
| __ror__ | The binary bitwise operation | with reflected operands |
| __rxor__ | The binary bitwise operation ^ with reflected operands |
| __rlshift__ | The binary bitwise operation << with reflected operands |
| __rrshift__ | The binary bitwise operation >> with reflected operands |
Augmented bitwise assignments
| __iand__ | The augmented bitwise assignment &= |
| __ior__ | The augmented bitwise assignment |= |
| __ixor__ | The augmented bitwise assignment ^= |
| __ilshift__ | The augmented bitwise assignment <<= |
| __irshift__ | The augmented bitwise assignment >>= |
Unary bitwise operators
| __invert__ | The unary bitwise operation ~ |
Standard library functions
| __deepcopy__ | Used if copy.deepcopy is called |
| __hash__ | The built-in function hash |
Container customization
| __len__ | The built-in function len |
| __getitem__ | Evaluation of self[indices] |
| __iter__ | Efficient iteration |
| __setitem__ | Assignment to self[indices] |
| __contains__ | Membership test operators |
String representations
| __repr__ | The built-in function repr |
| __str__ | The built-in function str |