MATLAB Function Reference    

Read formatted data from text file

    Graphical Interface

As an alternative to textread, use the Import Wizard. To activate the Import Wizard, select Import Data from the File menu.



[A,B,C,...] = textread('filename','format') reads data from the file 'filename' into the variables A,B,C, and so on, using the specified format, until the entire file is read. textread is useful for reading text files with a known format. Both fixed and free format files can be handled.

textread matches and converts groups of characters from the input. Each input field is defined as a string of non-whitespace characters that extends to the next whitespace or delimiter character, or to the maximum field width. Repeated delimiter characters are significant, while repeated whitespace characters are treated as one.

The format string determines the number and types of return arguments. The number of return arguments is the number of items in the format string. The format string supports a subset of the conversion specifiers and conventions of the C language fscanf routine. Values for the format string are listed in the table below. Whitespace characters in the format string are ignored.

(ordinary characters)
Ignore the matching characters. For example, in a file that has Dept followed by a number (for department number), to skip the Dept and read only the number, use 'Dept' in the format string.
Read a signed integer value.
Double array
Read an integer value.
Double array
Read a floating point value.
Double array
Read a whitespace or delimiter-
separated string.
Cell array of strings
Read a string, which could be in double quotes.
Cell array of strings. Does not include the double quotes.
Read characters, including white space.
Character array
Read the longest string containing characters specified in the brackets.
Cell array of strings
Read the longest non-empty string containing characters that are not specified in the brackets.
Cell array of strings
instead of %
Ignore the matching characters specified by *.
No output
instead of %
Read field width specified by w. The %f format supports, where w is the field width and p is the precision.

[A,B,C,...] = textread('filename','format',N) reads the data, reusing the format string N times, where N is an integer greater than zero. If N is smaller than zero, textread reads the entire file.

[...] = textread(...,'param','value',...) customizes textread using param/value pairs, as listed in the table below.

Any from the list below:
Treats vector of characters as whitespace. Default is ' \b\t'.

' '
New line
Carriage return
Horizontal tab
Delimiter character
Specifies delimiter character. Default is none.
Exponent characters
Default is eEdD.
positive integer
Specifies the maximum string length, in bytes. Default is 4095.
positive integer
Ignores the specified number of lines at the beginning of the file.
Ignores characters after %
Ignores characters after #.
Ignores characters between /* and */.
Ignores characters after //.


Example 1 - Read All Fields in Free Format File Using %

The first line of mydata.dat is

Read the first line of the file as a free format file using the % format.


Example 2 - Read as Fixed Format File, Ignoring the Floating Point Value

The first line of mydata.dat is

Read the first line of the file as a fixed format file, ignoring the floating point value.


%*f in the format string causes textread to ignore the floating point value, in this case, 12.34.

Example 3 - Read Using Literal to Ignore Matching Characters

The first line of mydata.dat is

Read the first line of the file, ignoring the characters Type in the second field.


Type%d in the format string causes the characters Type in the second field to be ignored, while the rest of the second field is read as a signed integer, in this case, 1.

Example 4 - Read M-file into a Cell Array of Strings

Read the file fft.m into cell array of strings.

See Also

dlmread, csvread, fscanf

  Text Properties textwrap