PYME.util.shmarray.shmarray module

shmarray.py

Shared memory array implementation for numpy which delegates all the nasty stuff to multiprocessing.sharedctypes.

Copyright (c) 2010, David Baddeley

PYME.util.shmarray.shmarray.create(shape, dtype='d', order=None)

Create an uninitialised shared array. Avoid object arrays, as these will almost certainly break as the objects themselves won’t be stored in shared memory, only the pointers

PYME.util.shmarray.shmarray.create_copy(a)

create a a shared copy of an array

PYME.util.shmarray.shmarray.ones(shape, dtype='d')

Create an shared array initialised to ones. Avoid object arrays, as these will almost certainly break as the objects themselves won’t be stored in shared memory, only the pointers

class PYME.util.shmarray.shmarray.shmarray

Bases: numpy.ndarray

subclass of ndarray with overridden pickling functions which record dtype, shape etc... but defer pickling of the underlying data to the original data source.

Doesn’t actually handle allocation of the shared memory - this is done in create, and zeros, ones, (or create_copy) are the functions which should be used for creating a new shared memory array.

TODO - add argument checking to ensure that the user is passing reasonable values.

Attributes

T Same as self.transpose(), except that self is returned if self.ndim < 2.
base Base object if memory is from some other object.
ctypes An object to simplify the interaction of the array with the ctypes module.
data Python buffer object pointing to the start of the array’s data.
dtype Data-type of the array’s elements.
flags Information about the memory layout of the array.
flat A 1-D iterator over the array.
imag The imaginary part of the array.
itemsize Length of one array element in bytes.
nbytes Total bytes consumed by the elements of the array.
ndim Number of array dimensions.
real The real part of the array.
shape Tuple of array dimensions.
size Number of elements in the array.
strides Tuple of bytes to step in each dimension when traversing an array.

Methods

all([axis, out, keepdims]) Returns True if all elements evaluate to True.
any([axis, out, keepdims]) Returns True if any of the elements of a evaluate to True.
argmax([axis, out]) Return indices of the maximum values along the given axis.
argmin([axis, out]) Return indices of the minimum values along the given axis of a.
argpartition(kth[, axis, kind, order]) Returns the indices that would partition this array.
argsort([axis, kind, order]) Returns the indices that would sort this array.
astype(dtype[, order, casting, subok, copy]) Copy of the array, cast to a specified type.
byteswap(inplace) Swap the bytes of the array elements
choose(choices[, out, mode]) Use an index array to construct a new array from a set of choices.
clip([min, max, out]) Return an array whose values are limited to [min, max].
compress(condition[, axis, out]) Return selected slices of this array along given axis.
conj() Complex-conjugate all elements.
conjugate() Return the complex conjugate, element-wise.
copy([order]) Return a copy of the array.
cumprod([axis, dtype, out]) Return the cumulative product of the elements along the given axis.
cumsum([axis, dtype, out]) Return the cumulative sum of the elements along the given axis.
diagonal([offset, axis1, axis2]) Return specified diagonals.
dot(b[, out]) Dot product of two arrays.
dump(file) Dump a pickle of the array to the specified file.
dumps() Returns the pickle of the array as a string.
fill(value) Fill the array with a scalar value.
flatten([order]) Return a copy of the array collapsed into one dimension.
getfield(dtype[, offset]) Returns a field of the given array as a certain type.
item(*args) Copy an element of an array to a standard Python scalar and return it.
itemset(*args) Insert scalar into an array (scalar is cast to array’s dtype, if possible)
max([axis, out]) Return the maximum along a given axis.
mean([axis, dtype, out, keepdims]) Returns the average of the array elements along given axis.
min([axis, out, keepdims]) Return the minimum along a given axis.
newbyteorder([new_order]) Return the array with the same data viewed with a different byte order.
nonzero() Return the indices of the elements that are non-zero.
partition(kth[, axis, kind, order]) Rearranges the elements in the array in such a way that value of the element in kth position is in the position it would be in a sorted array.
prod([axis, dtype, out, keepdims]) Return the product of the array elements over the given axis
ptp([axis, out]) Peak to peak (maximum - minimum) value along a given axis.
put(indices, values[, mode]) Set a.flat[n] = values[n] for all n in indices.
ravel([order]) Return a flattened array.
repeat(repeats[, axis]) Repeat elements of an array.
reshape(shape[, order]) Returns an array containing the same data with a new shape.
resize(new_shape[, refcheck]) Change shape and size of array in-place.
round([decimals, out]) Return a with each element rounded to the given number of decimals.
searchsorted(v[, side, sorter]) Find indices where elements of v should be inserted in a to maintain order.
setfield(val, dtype[, offset]) Put a value into a specified place in a field defined by a data-type.
setflags([write, align, uic]) Set array flags WRITEABLE, ALIGNED, and UPDATEIFCOPY, respectively.
sort([axis, kind, order]) Sort an array, in-place.
squeeze([axis]) Remove single-dimensional entries from the shape of a.
std([axis, dtype, out, ddof, keepdims]) Returns the standard deviation of the array elements along given axis.
sum([axis, dtype, out, keepdims]) Return the sum of the array elements over the given axis.
swapaxes(axis1, axis2) Return a view of the array with axis1 and axis2 interchanged.
take(indices[, axis, out, mode]) Return an array formed from the elements of a at the given indices.
tobytes([order]) Construct Python bytes containing the raw data bytes in the array.
tofile(fid[, sep, format]) Write array to a file as text or binary (default).
tolist() Return the array as a (possibly nested) list.
tostring([order]) Construct Python bytes containing the raw data bytes in the array.
trace([offset, axis1, axis2, dtype, out]) Return the sum along diagonals of the array.
transpose(*axes) Returns a view of the array with axes transposed.
var([axis, dtype, out, ddof, keepdims]) Returns the variance of the array elements, along given axis.
view([dtype, type]) New view of array with the same data.
PYME.util.shmarray.shmarray.zeros(shape, dtype='d', order=None)

Create an shared array initialised to zeros. Avoid object arrays, as these will almost certainly break as the objects themselves won’t be stored in shared memory, only the pointers