MATLAB Function Reference |
Syntax
Description
A = fscanf(fid, format)
reads all the data from the file specified by fid
, converts it according to the specified format
string, and returns it in matrix A
. Argument fid
is an integer file identifier obtained from fopen
. format
is a string specifying the format of the data to be read. See "Remarks" for details.
[A,count] = fscanf(fid, format, size)
reads the amount of data specified by size
, converts it according to the specified format
string, and returns it along with a count
of elements successfully read. size
is an argument that determines how much data is read. Valid options are
fscanf differs from its C language namesakes scanf()
and fscanf
()
in an important respect -- it is vectorized in order to return a matrix argument. The format
string is cycled through the file until an end-of-file is reached or the amount of data specified by size
is read in.
Remarks
When MATLAB reads a specified file, it attempts to match the data in the file to the format
string. If a match occurs, the data is written into the matrix in column order. If a partial match occurs, only the matching data is written to the matrix, and the read operation stops.
The format
string consists of ordinary characters and/or conversion specifications. Conversion specifications indicate the type of data to be matched and involve the character %
, optional width fields, and conversion characters, organized as shown below.
Add one or more of these characters between the %
and the conversion character:
Valid conversion characters are
If %s
is used, an element read can use several MATLAB matrix elements, each holding one character. Use %c
to read space characters or %s
to skip all white space.
Mixing character and numeric conversion specifications causes the resulting matrix to be numeric and any characters read to appear as their ASCII values, one character per MATLAB matrix element.
For more information about format strings, refer to the scanf()
and fscanf()
routines in a C language reference manual.
Examples
The example in fprintf
generates an ASCII text file called exp.txt
that looks like
Read this ASCII file back into a two-column MATLAB matrix:
fid = fopen('exp.txt', 'r'); a = fscanf(fid, '%g %g', [2 inf]) % It has two rows now. a = a'; fclose(fid)
See Also
fgetl
, fgets
, fread
, fprintf
, fscanf
, input
, sscanf
, textread
frewind | fseek |
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