MMP#

Interface to numpy memmaps

Note

For image processing we use [x,y,z] order of arrays. To speed up access to z-planes memmaps are created in Fortran order by default.

class Source(location=None, shape=None, dtype=None, order=None, array=None, mode=None, name=None)[source]#

Bases: Source

Memory mapped array source.

as_buffer()[source]#

as_virtual()[source]#

Return virtual source without array data to pass in parallel processing.

Returns

sourceSource class: The source class without array data.

property array#

The underlying data array.

Returns

arrayarray or np.ndarray: The underlying data array of this source.

property dtype#

The data type of the source.

Returns

dtypedtype: The data type of the source.

property location#

The location where the data of the source is stored.

Returns

locationstr or None: Returns the location of the data source or None if this source lives in memory only.

property mode#

property offset#

The offset of the memory map in the file.

Returns

offsetint: Offset of the memory map in the file.

property order#

The order of how the data is stored in the source.

Returns

orderstr: Returns ‘C’ for C contiguous and ‘F’ for Fortran contiguous, None otherwise.

class VirtualSource(source=None, shape=None, dtype=None, order=None, name=None, mode=None)[source]#

Bases: VirtualSource

Virtual memory map source.

as_real()[source]#: Default: reopen from location with mode. Override in modules that need extra constructor args.

property array#

create(location=None, shape=None, dtype=None, order=None, mode=None, array=None, as_source=True, **kwargs)[source]#

Create a memory map.

Arguments

locationstr: The filename of the memory mapped array.
shapetuple or None: The shape of the memory map to create.
dtypedtype: The data type of the memory map.
order‘C’, ‘F’, or None: The contiguous order of the memmap.
mode‘r’, ‘w’, ‘w+’, None: The mode to open the memory map.
arrayarray, Source or None: Optional source with data to fill the memory map with.
as_sourcebool: If True, return as Source class.

Returns

memmapnp.memmap: The memory map.

Note

By default memmaps are initialized as Fortran contiguous if order is None.

edit(source, **kwargs)[source]#: Open an existing memmap for in-place modification.

header_size(filename)[source]#

Return the offset of a header in a memmaped file.

Arguments

filenamestr: Filename of the npy fie.

Returns

offsetint: The offest due to the header.

is_memmap(source)[source]#

open_ro(source, **kwargs)[source]#: Open a source strictly read-only for metadata queries.

read(source, slicing=None, mode=None, **kwargs)[source]#

Read data from a memory mapped source.

Arguments

sourcestr, memmap, or Source: The source to read the data from.
slicingslice specification: Optional slice specification of memmap to read from.
modestr: Optional mode specification of how to open the memmap.

Returns

sourceSource: The read memmap source.

write(sink, data, slicing=None, **kwargs)[source]#

Write data to a memory map.

Arguments

sinkstr, memmap, or Source: The sink to write the data to.
dataarray: The data to write int the sink.
slicingslice specification or None: Optional slice specification of an existing memmap to write to.

Returns

sinkstr, memmap, or Source: The sink.