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author | Jarrod Millman <millman@berkeley.edu> | 2010-02-17 23:55:16 +0000 |
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committer | Jarrod Millman <millman@berkeley.edu> | 2010-02-17 23:55:16 +0000 |
commit | 1c7167378e9f654a80b3cb57b7c0dd7ee573a109 (patch) | |
tree | 1926d178db2e66c19552f8216926c07155f7cde3 /doc/source/reference/arrays.ndarray.rst | |
parent | e2bb09430d90c73a7be6e47ea8c4528f094f693f (diff) | |
download | numpy-1c7167378e9f654a80b3cb57b7c0dd7ee573a109.tar.gz |
updated documentation from pydoc website (thanks to everyone who contributed!)
Diffstat (limited to 'doc/source/reference/arrays.ndarray.rst')
-rw-r--r-- | doc/source/reference/arrays.ndarray.rst | 65 |
1 files changed, 29 insertions, 36 deletions
diff --git a/doc/source/reference/arrays.ndarray.rst b/doc/source/reference/arrays.ndarray.rst index 0cad2ac6e..c14e6869a 100644 --- a/doc/source/reference/arrays.ndarray.rst +++ b/doc/source/reference/arrays.ndarray.rst @@ -9,9 +9,9 @@ The N-dimensional array (:class:`ndarray`) An :class:`ndarray` is a (usually fixed-size) multidimensional container of items of the same type and size. The number of dimensions and items in an array is defined by its :attr:`shape <ndarray.shape>`, -which is a :class:`tuple` of *N* positive integers that specify the sizes of -each dimension. The type of items in the array is specified by a -separate :ref:`data-type object (dtype) <arrays.dtypes>`, one of which +which is a :class:`tuple` of *N* positive integers that specify the +sizes of each dimension. The type of items in the array is specified by +a separate :ref:`data-type object (dtype) <arrays.dtypes>`, one of which is associated with each ndarray. As with other container objects in Python, the contents of an @@ -32,7 +32,8 @@ objects implementing the :class:`buffer` or :ref:`array .. admonition:: Example - A 2-dimensional array of size 2 x 3, composed of 4-byte integer elements: + A 2-dimensional array of size 2 x 3, composed of 4-byte integer + elements: >>> x = np.array([[1, 2, 3], [4, 5, 6]], np.int32) >>> type(x) @@ -44,10 +45,11 @@ objects implementing the :class:`buffer` or :ref:`array The array can be indexed using Python container-like syntax: - >>> x[1,2] # i.e., the element of x in the *second* row, *third* column - 6 + >>> x[1,2] # i.e., the element of x in the *second* row, *third* + column, namely, 6. - For example :ref:`slicing <arrays.indexing>` can produce views of the array: + For example :ref:`slicing <arrays.indexing>` can produce views of + the array: >>> y = x[:,1] >>> y @@ -96,14 +98,15 @@ which the indices can vary is specified by the :obj:`shape the bytes are interpreted is defined by the :ref:`data-type object <arrays.dtypes>` associated with the array. -.. index:: C-order, Fortran-order, row-major, column-major, stride, offset +.. index:: C-order, Fortran-order, row-major, column-major, stride, + offset A segment of memory is inherently 1-dimensional, and there are many -different schemes for arranging the items of an *N*-dimensional array in -a 1-dimensional block. Numpy is flexible, and :class:`ndarray` objects -can accommodate any *strided indexing scheme*. In a strided scheme, -the N-dimensional index :math:`(n_0, n_1, ..., n_{N-1})` corresponds -to the offset (in bytes) +different schemes for arranging the items of an *N*-dimensional array +in a 1-dimensional block. Numpy is flexible, and :class:`ndarray` +objects can accommodate any *strided indexing scheme*. In a strided +scheme, the N-dimensional index :math:`(n_0, n_1, ..., n_{N-1})` +corresponds to the offset (in bytes): .. math:: n_{\mathrm{offset}} = \sum_{k=0}^{N-1} s_k n_k @@ -116,7 +119,8 @@ strided scheme, and correspond to the strides: .. math:: - s_k^{\mathrm{column}} = \prod_{j=0}^{k-1} d_j , \quad s_k^{\mathrm{row}} = \prod_{j=k+1}^{N-1} d_j . + s_k^{\mathrm{column}} = \prod_{j=0}^{k-1} d_j , + \quad s_k^{\mathrm{row}} = \prod_{j=k+1}^{N-1} d_j . .. index:: single-segment, contiguous, non-contiguous @@ -172,8 +176,6 @@ of the array: ndarray.nbytes ndarray.base -.. note:: XXX: update and check these docstrings. - Data type --------- @@ -187,8 +189,6 @@ The data type object associated with the array can be found in the ndarray.dtype -.. note:: XXX: update the dtype attribute docstring: setting etc. - Other attributes ---------------- @@ -223,9 +223,6 @@ Array interface ndarray.ctypes -.. note:: XXX: update and check these docstrings. - - .. _array.ndarray.methods: Array methods @@ -241,11 +238,12 @@ For the following methods there are also corresponding functions in :func:`argmin`, :func:`argsort`, :func:`choose`, :func:`clip`, :func:`compress`, :func:`copy`, :func:`cumprod`, :func:`cumsum`, :func:`diagonal`, :func:`imag`, :func:`max <amax>`, :func:`mean`, -:func:`min <amin>`, :func:`nonzero`, :func:`prod`, :func:`ptp`, :func:`put`, -:func:`ravel`, :func:`real`, :func:`repeat`, :func:`reshape`, -:func:`round <around>`, :func:`searchsorted`, :func:`sort`, :func:`squeeze`, -:func:`std`, :func:`sum`, :func:`swapaxes`, :func:`take`, -:func:`trace`, :func:`transpose`, :func:`var`. +:func:`min <amin>`, :func:`nonzero`, :func:`prod`, :func:`ptp`, +:func:`put`, :func:`ravel`, :func:`real`, :func:`repeat`, +:func:`reshape`, :func:`round <around>`, :func:`searchsorted`, +:func:`sort`, :func:`squeeze`, :func:`std`, :func:`sum`, +:func:`swapaxes`, :func:`take`, :func:`trace`, :func:`transpose`, +:func:`var`. Array conversion ---------------- @@ -268,8 +266,6 @@ Array conversion ndarray.setflags ndarray.fill -.. note:: XXX: update and check these docstrings. - Shape manipulation ------------------ @@ -323,8 +319,8 @@ Many of these methods take an argument named *axis*. In such cases, float32, float64, etc., whereas a 0-dimensional array is an ndarray instance containing precisely one array scalar.) -- If *axis* is an integer, then the operation is done over the given axis - (for each 1-D subarray that can be created along the given axis). +- If *axis* is an integer, then the operation is done over the given + axis (for each 1-D subarray that can be created along the given axis). .. admonition:: Example of the *axis* argument @@ -393,9 +389,6 @@ be performed. Arithmetic and comparison operations ==================================== -.. note:: XXX: write all attributes explicitly here instead of relying on - the auto\* stuff? - .. index:: comparison, arithmetic, operation, operator Arithmetic and comparison operations on :class:`ndarrays <ndarray>` @@ -435,9 +428,9 @@ Truth value of an array (:func:`bool()`): :meth:`ndarray.__nonzero__`, which raises an error if the number of elements in the the array is larger than 1, because the truth value of such arrays is ambiguous. Use :meth:`.any() <ndarray.any>` and - :meth:`.all() <ndarray.all>` instead to be clear about what is meant in - such cases. (If the number of elements is 0, the array evaluates to - ``False``.) + :meth:`.all() <ndarray.all>` instead to be clear about what is meant + in such cases. (If the number of elements is 0, the array evaluates + to ``False``.) Unary operations: |