dbarray
src.dbarray.DBArray Class Reference

Array stored in database. More...

List of all members.

Public Member Functions

def __init__
 Initialize the `DBArray`.
def __del__
 Destroy the `DBArray`.
def __len__
 Get number of rows.
def __getitem__
 Get a subarray from DB.
def __setitem__
 Set a subarray in DB.
def set_shape
 Set shape of `DBArray`.
def set_dtype
 Set dtype of `DBArray`.
def get_rows
 Get rows from DB.
def set_rows
 Set rows of DB.
def get_row
 Get a row.
def set_row
 Set a row.
def set_db_attr
 Set DB attribute.
def get_db_attr
 Set DB attribute.
def fromndarray
 Construct `DBArray` from `ndarray`.
def tondarray
 Load data to `ndarray` from `DBArray`.

Public Attributes

 nrows
 Number of rows in the array.
 ncols
 Number of cols in the array.
 dtype
 Associated data-type describes the format of each element in the array, which is compact with `numpy`.

Detailed Description

Array stored in database.

`DBArray` is an 2D array stored in database. The purpose of this class is to provide a way to store and access large array which can not be loaded into memory.

An associated data-type object describes the format of each element in the array. (The data-type is compact with `numpy`)


Constructor & Destructor Documentation

def src.dbarray.DBArray.__init__ (   self,
  dbpath,
  dbtype = DEFAULT_DTYPE 
)

Initialize the `DBArray`.

Args: `dbpath` [str] path of the database. `dbtype` [str] type of the database.

Returns: N/A

Destroy the `DBArray`.

Args: N/A

Returns: N/A


Member Function Documentation

def src.dbarray.DBArray.__getitem__ (   self,
  key 
)

Get a subarray from DB.

Args: `key` [str, integer, slice or tuple] An `key` of type `str` corresponds to an attribute. Other kinds of `key`s correspond to array indices.

Returns: `attr` [str, int or numpy.ndarray] for `key` of type `str`. `subarray` [numpy.ndarray] for `key` of other types.

def src.dbarray.DBArray.__setitem__ (   self,
  key,
  val 
)

Set a subarray in DB.

Args: `key` [str, integer, slice or tuple] An `key` of type `str` corresponds to an attribute. Other kinds of `key`s correspond to array indices. `val` [str, int or numpy.ndarray] for `key` of type `str`. [numpy.ndarray] for `key` of other types.

Returns: N/A

def src.dbarray.DBArray.fromndarray (   cls,
  arr,
  dbpath,
  dbtype = DEFAULT_DTYPE 
)

Construct `DBArray` from `ndarray`.

Args: `arr` [numpy.ndarray] The source `ndarray`. `dbpath` [str] Path of the database. `dbtype` [str] Type of the database.

Returns: `dba` [DBArray]

def src.dbarray.DBArray.get_db_attr (   self,
  key 
)

Set DB attribute.

Args: `key` [str] Name of the attribute.

Returns: `val` [str, int or 1-row numpy.ndarray] Value of the attribute.

def src.dbarray.DBArray.get_row (   self,
  rid 
)

Get a row.

Args: `rid` [int] A single row Id.

Returns: `subarray` [numpy.ndarray] Row vector specified by `rid`.

def src.dbarray.DBArray.get_rows (   self,
  v_rid 
)

Get rows from DB.

Args: `v_rid` [list of int] A list of row Ids.

Returns: `subarray` [numpy.ndarray] rows specified by `v_rid`.

def src.dbarray.DBArray.set_db_attr (   self,
  key,
  val 
)

Set DB attribute.

Args: `key` [str] Name of the attribute. `val` [str, int or 1-row numpy.ndarray] Value of the attribute. The following attribute type are supported: 'nda': numpy.ndarray 'int': int 'str': string

Returns: N/A

def src.dbarray.DBArray.set_dtype (   self,
  dtype 
)

Set dtype of `DBArray`.

Args: `dtype` [str or numpy.dtype] Can be any valid numpy.dtype.

Returns: N/A

def src.dbarray.DBArray.set_row (   self,
  rid,
  arr 
)

Set a row.

Args: `rid` [int] A single row Id. `arr` [numpy.ndarray] Row vector specified by `rid`.

Returns: N/A

def src.dbarray.DBArray.set_rows (   self,
  v_rid,
  arr 
)

Set rows of DB.

Args: `v_rid` [list of int] A list of row Ids. `arr` [numpy.ndarray] Rows specified by `v_rid`.

Returns: N/A

def src.dbarray.DBArray.set_shape (   self,
  shape 
)

Set shape of `DBArray`.

Args: `shape` [tuple of int: (nrows, ncols)] Specify number of rows and cols of `DBArray`.

Returns: N/A

Load data to `ndarray` from `DBArray`.

Args: N/A

Returns: `arr` [numpy.ndarray]


The documentation for this class was generated from the following file:
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