MATLAB Programming

6 Data Import and Export
Writable: false
Offset: 0
Format: 'uint8'
Repeat: Inf
Data: 40000x1 uint8 array
MATLAB constructs an instance of the memmapfile class, assigns it to the
variable m, andmapstheentirerecords.dat file to memory, setting all
properties of the object to their default values. In this example, the command
maps the entire file as a sequence of unsigned 8-bit integers, and gives the
caller read-only access to its contents.
Changing Property Values
You can make the memory map more specific to your needs by including
more information when calling the constructor. In addition to the filename
argument, there are four other parameters that you can pass to the
constructor. Each of these parameters represents a property of the object, and
each requires an accompanying value to be passed as well:
objname = memmapfile(filename, prop1, value1, prop2, value2, ...)
For example, to construct a map using nondefault values for the Offset,
Format, andWritable properties, type the following, enclosing all property
names and string parameter values in quotes:
m = memmapfile('records.dat', ...
'Offset', 1024, ...
'Format', 'double', ...
'Writable', true);
Typetheobjectnametoseethecurrentsettingsforallproperties:
m
m =
Filename: 'd:\matlab\mfiles\records.dat'
Writable: true
Offset: 1024
Format: 'double'
Repeat: Inf
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