MATLAB Programming

6 Data Import and Export
Use these functions to create temporary files. Some systems delete temporary
files every time you reboot the system. On other systems, designating a file as
temporary can mean only that the file is not backed up.
The tempdir function returns the name of the directory or folder that has
been designated to hold temporary files on your system. For example, issuing
tempdir on a UNIX system returns the /tmp directory.
MATLAB also provides a tempname function that returns afilenameinthe
temporary directory. The returned filename is a suitable destination for
temporary data. For example, if you need to store some data in a temporary
file, then you might issue the following command first:
fid = fopen(tempname, 'w');
Note The filename that tempname generates is not guaranteed to be unique;
however, it is likely to be so.
Reading Binary Data
The fread function reads all or part of a binary file (as specified by a file
identifier) and stores it in a matrix. In its simplest form, it reads an entire
file and interprets each byte of input as the next element of the matrix. For
example, the following code reads the data from a file named nickel.dat
into matrix A:
fid = fopen('nickel.dat','r');
A = fread(fid);
To echo the data to the screen after reading it, use char to display the contents
of A as characters, transposing the data so it is displayed horizontally:
disp(char(A'))
The char function causes MATLAB to interpret the contents of A as characters
instead of as numbers. Transposing A displays it in its more natural
horizontal format.
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