diff options
Diffstat (limited to 'numpy/core/numeric.py')
| -rw-r--r-- | numpy/core/numeric.py | 41 |
1 files changed, 37 insertions, 4 deletions
diff --git a/numpy/core/numeric.py b/numpy/core/numeric.py index b2f141312..6b35d2ab9 100644 --- a/numpy/core/numeric.py +++ b/numpy/core/numeric.py @@ -40,10 +40,11 @@ BUFSIZE = multiarray.BUFSIZE # from Fernando Perez's IPython def zeros_like(a): - """Return an array of zeros of the shape and typecode of a. + """Return an array of zeros of the shape and data-type of a. If you don't explicitly need the array to be zeroed, you should instead - use empty_like(), which is faster as it only allocates memory.""" + use empty_like(), which is faster as it only allocates memory. + """ try: return zeros(a.shape, a.dtype, a.flags.fnc) except AttributeError: @@ -58,7 +59,7 @@ def zeros_like(a): return res def empty_like(a): - """Return an empty (uninitialized) array of the shape and typecode of a. + """Return an empty (uninitialized) array of the shape and data-type of a. Note that this does NOT initialize the returned array. If you require your array to be initialized, you should use zeros_like(). @@ -147,6 +148,29 @@ def asfortranarray(a, dtype=None): return array(a, dtype, copy=False, order='F', ndmin=1) def require(a, dtype=None, requirements=None): + """Return an ndarray of the provided type that satisfies requirements. + + This function is useful to be sure that an array with the correct flags + is returned for passing to compiled code (perhaps through ctypes). + + Parameters + ---------- + a : array-like + The object to be converted to a type-and-requirement satisfying array + dtype : data-type + The required data-type (None is the default data-type -- float64) + requirements : list of strings + The requirements list can be any of the + 'ENSUREARRAY' ('E') - ensure that a base-class ndarray + 'F_CONTIGUOUS' ('F') - ensure a Fortran-contiguous array + 'C_CONTIGUOUS' ('C') - ensure a C-contiguous array + 'ALIGNED' ('A') - ensure a data-type aligned array + 'WRITEABLE' ('W') - ensure a writeable array + 'OWNDATA' ('O') - ensure an array that owns its own data + + The returned array will be guaranteed to have the listed requirements + by making a copy if needed. + """ if requirements is None: requirements = [] else: @@ -252,11 +276,13 @@ def vdot(a, b): try: # importing this changes the dot function for basic 4 types # to blas-optimized versions. - from _dotblas import dot, vdot, inner, alterdot, restoredot + from _dotblas import dot, vdot, inner, alterdot, restoredot except ImportError: def alterdot(): + "Does Nothing" pass def restoredot(): + "Does Nothing" pass @@ -847,6 +873,9 @@ def allclose(a, b, rtol=1.e-5, atol=1.e-8): return all(less_equal(absolute(x-y), atol + rtol * absolute(y))) def array_equal(a1, a2): + """Returns True if a1 and a2 have identical shapes + and all elements equal and False otherwise. + """ try: a1, a2 = asarray(a1), asarray(a2) except: @@ -856,6 +885,10 @@ def array_equal(a1, a2): return logical_and.reduce(equal(a1,a2).ravel()) def array_equiv(a1, a2): + """Returns True if a1 and a2 are shape consistent + (mutually broadcastable) and have all elements equal and False + otherwise. + """ try: a1, a2 = asarray(a1), asarray(a2) except: |