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<div class="subsection" id="Numerical-Data-and-Strings">
<div class="header">
<p>
Next: <a href="JSON-data-encoding_002fdecoding.html" accesskey="n" rel="next">JSON data encoding/decoding</a>, Previous: <a href="String-encoding.html" accesskey="p" rel="prev">String encoding</a>, Up: <a href="Converting-Strings.html" accesskey="u" rel="up">Converting Strings</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<span id="Numerical-Data-and-Strings-1"></span><h4 class="subsection">5.4.2 Numerical Data and Strings</h4>

<p>Apart from the string concatenation functions (see <a href="Concatenating-Strings.html">Concatenating Strings</a>)
which cast numerical data to the corresponding UTF-8 encoded characters, there
are several functions that format numerical data as strings.  <code>mat2str</code>
and <code>num2str</code> convert real or complex matrices, while <code>int2str</code>
converts integer matrices.  <code>int2str</code> takes the real part of complex
values and round fractional values to integer.  A more flexible way to format
numerical data as strings is the <code>sprintf</code> function
(see <a href="Formatted-Output.html">Formatted Output</a>, <a href="Formatted-Output.html#XREFsprintf">sprintf</a>).
</p>
<span id="XREFmat2str"></span><dl class="def">
<dt id="index-mat2str"><span class="category">: </span><span><em><var>s</var> =</em> <strong>mat2str</strong> <em>(<var>x</var>, <var>n</var>)</em><a href='#index-mat2str' class='copiable-anchor'> &para;</a></span></dt>
<dt id="index-mat2str-1"><span class="category">: </span><span><em><var>s</var> =</em> <strong>mat2str</strong> <em>(<var>x</var>, <var>n</var>, &quot;class&quot;)</em><a href='#index-mat2str-1' class='copiable-anchor'> &para;</a></span></dt>
<dd><p>Format real, complex, and logical matrices as strings.
</p>
<p>The returned string may be used to reconstruct the original matrix by using
the <code>eval</code> function.
</p>
<p>The precision of the values is given by <var>n</var>.  If <var>n</var> is a scalar
then both real and imaginary parts of the matrix are printed to the same
precision.  Otherwise <code><var>n</var>(1)</code> defines the precision of the real
part and <code><var>n</var>(2)</code> defines the precision of the imaginary part.
The default for <var>n</var> is 15.
</p>
<p>If the argument <code>&quot;class&quot;</code> is given then the class of <var>x</var> is
included in the string in such a way that <code>eval</code> will result in the
construction of a matrix of the same class.
</p>
<div class="example">
<pre class="example">mat2str ([ -1/3 + i/7; 1/3 - i/7 ], [4 2])
     &rArr; &quot;[-0.3333+0.14i;0.3333-0.14i]&quot;

mat2str ([ -1/3 +i/7; 1/3 -i/7 ], [4 2])
     &rArr; &quot;[-0.3333+0i 0+0.14i;0.3333+0i -0-0.14i]&quot;

mat2str (int16 ([1 -1]), &quot;class&quot;)
     &rArr; &quot;int16([1 -1])&quot;

mat2str (logical (eye (2)))
     &rArr; &quot;[true false;false true]&quot;

isequal (x, eval (mat2str (x)))
     &rArr; 1
</pre></div>


<p><strong>See also:</strong> <a href="Formatted-Output.html#XREFsprintf">sprintf</a>, <a href="#XREFnum2str">num2str</a>, <a href="#XREFint2str">int2str</a>.
</p></dd></dl>


<span id="XREFnum2str"></span><dl class="def">
<dt id="index-num2str"><span class="category">: </span><span><em></em> <strong>num2str</strong> <em>(<var>x</var>)</em><a href='#index-num2str' class='copiable-anchor'> &para;</a></span></dt>
<dt id="index-num2str-1"><span class="category">: </span><span><em></em> <strong>num2str</strong> <em>(<var>x</var>, <var>precision</var>)</em><a href='#index-num2str-1' class='copiable-anchor'> &para;</a></span></dt>
<dt id="index-num2str-2"><span class="category">: </span><span><em></em> <strong>num2str</strong> <em>(<var>x</var>, <var>format</var>)</em><a href='#index-num2str-2' class='copiable-anchor'> &para;</a></span></dt>
<dd><p>Convert a number (or array) to a string (or a character array).
</p>
<p>The optional second argument may either give the number of significant
digits (<var>precision</var>) to be used in the output or a format template
string (<var>format</var>) as in <code>sprintf</code> (see <a href="Formatted-Output.html">Formatted Output</a>).
<code>num2str</code> can also process complex numbers.
</p>
<p>Examples:
</p>
<div class="example">
<pre class="example">num2str (123.456)
  &rArr; 123.456

num2str (123.456, 4)
  &rArr; 123.5

s = num2str ([1, 1.34; 3, 3.56], &quot;%5.1f&quot;)
  &rArr; s =
       1.0  1.3
       3.0  3.6
whos s
  &rArr; Variables in the current scope:
        Attr Name        Size                     Bytes  Class
        ==== ====        ====                     =====  =====
             s           2x8                         16  char
     Total is 16 elements using 16 bytes

num2str (1.234 + 27.3i)
  &rArr; 1.234+27.3i
</pre></div>

<p>The <code>num2str</code> function is not very flexible.  For better control
over the results, use <code>sprintf</code> (see <a href="Formatted-Output.html">Formatted Output</a>).
</p>
<p>Programming Notes:
</p>
<p>For <small>MATLAB</small> compatibility, leading spaces are stripped before returning
the string.
</p>
<p>Integers larger than <code>flintmax</code> may not be displayed correctly.
</p>
<p>For complex <var>x</var>, the format string may only contain one output
conversion specification and nothing else.  Otherwise, results will be
unpredictable.
</p>
<p>Any optional <var>format</var> specified by the programmer is used without
modification.  This is in contrast to <small>MATLAB</small> which tampers with the
<var>format</var> based on internal heuristics.
</p>
<p><strong>See also:</strong> <a href="Formatted-Output.html#XREFsprintf">sprintf</a>, <a href="#XREFint2str">int2str</a>, <a href="#XREFmat2str">mat2str</a>.
</p></dd></dl>


<span id="XREFint2str"></span><dl class="def">
<dt id="index-int2str"><span class="category">: </span><span><em></em> <strong>int2str</strong> <em>(<var>n</var>)</em><a href='#index-int2str' class='copiable-anchor'> &para;</a></span></dt>
<dd><p>Convert an integer (or array of integers) to a string (or a character
array).
</p>
<div class="example">
<pre class="example">int2str (123)
  &rArr; 123

s = int2str ([1, 2, 3; 4, 5, 6])
  &rArr; s =
        1  2  3
        4  5  6

whos s
  &rArr; Variables in the current scope:
        Attr Name        Size                     Bytes  Class
        ==== ====        ====                     =====  =====
             s           2x7                         14  char
     Total is 14 elements using 14 bytes
</pre></div>

<p>This function is not very flexible.  For better control over the
results, use <code>sprintf</code> (see <a href="Formatted-Output.html">Formatted Output</a>).
</p>
<p>Programming Notes:
</p>
<p>Non-integers are rounded to integers before display.  Only the real part
of complex numbers is displayed.
</p>

<p><strong>See also:</strong> <a href="Formatted-Output.html#XREFsprintf">sprintf</a>, <a href="#XREFnum2str">num2str</a>, <a href="#XREFmat2str">mat2str</a>.
</p></dd></dl>


<span id="XREFstr2double"></span><dl class="def">
<dt id="index-str2double"><span class="category">: </span><span><em></em> <strong>str2double</strong> <em>(<var>s</var>)</em><a href='#index-str2double' class='copiable-anchor'> &para;</a></span></dt>
<dd><p>Convert a string to a real or complex number.
</p>
<p>The string must be in one of the following formats where a and b are real
numbers and the complex unit is <code>'i'</code> or <code>'j'</code>:
</p>
<ul>
<li> a + bi

</li><li> a + b*i

</li><li> a + i*b

</li><li> bi + a

</li><li> b*i + a

</li><li> i*b + a
</li></ul>

<p>If present, a and/or b are of the form [+-]d[,.]d[[eE][+-]d] where
the brackets indicate optional arguments and <code>'d'</code> indicates zero or
more digits.  The special input values <code>Inf</code>, <code>NaN</code>, and <code>NA</code>
are also accepted.
</p>
<p><var>s</var> may be a character string, character matrix, or cell array.  For
character arrays the conversion is repeated for every row, and a double or
complex array is returned.  Empty rows in <var>s</var> are deleted and not
returned in the numeric array.  For cell arrays each character string
element is processed and a double or complex array of the same dimensions as
<var>s</var> is returned.
</p>
<p>For unconvertible scalar or character string input <code>str2double</code> returns
a NaN.  Similarly, for character array input <code>str2double</code> returns a
NaN for any row of <var>s</var> that could not be converted.  For a cell array,
<code>str2double</code> returns a NaN for any element of <var>s</var> for which
conversion fails.  Note that numeric elements in a mixed string/numeric
cell array are not strings and the conversion will fail for these elements
and return NaN.
</p>
<p><code>str2double</code> can replace <code>str2num</code>, and it avoids the security
risk of using <code>eval</code> on unknown data.
</p>
<p><strong>See also:</strong> <a href="#XREFstr2num">str2num</a>.
</p></dd></dl>


<span id="XREFstr2num"></span><dl class="def">
<dt id="index-str2num"><span class="category">: </span><span><em><var>x</var> =</em> <strong>str2num</strong> <em>(<var>s</var>)</em><a href='#index-str2num' class='copiable-anchor'> &para;</a></span></dt>
<dt id="index-str2num-1"><span class="category">: </span><span><em>[<var>x</var>, <var>state</var>] =</em> <strong>str2num</strong> <em>(<var>s</var>)</em><a href='#index-str2num-1' class='copiable-anchor'> &para;</a></span></dt>
<dd><p>Convert the string (or character array) <var>s</var> to a number (or an array).
</p>
<p>Examples:
</p>
<div class="example">
<pre class="example">str2num (&quot;3.141596&quot;)
      &rArr; 3.141596

str2num ([&quot;1, 2, 3&quot;; &quot;4, 5, 6&quot;])
      &rArr; 1  2  3
         4  5  6
</pre></div>

<p>The optional second output, <var>state</var>, is logically true when the
conversion is successful.  If the conversion fails the numeric output,
<var>x</var>, is empty and <var>state</var> is false.
</p>
<p><strong>Caution:</strong> As <code>str2num</code> uses the <code>eval</code> function to do the
conversion, <code>str2num</code> will execute any code contained in the string
<var>s</var>.  Use <code>str2double</code> for a safer and faster conversion.
</p>
<p>For cell array of strings use <code>str2double</code>.
</p>
<p><strong>See also:</strong> <a href="#XREFstr2double">str2double</a>, <a href="Evaluation.html#XREFeval">eval</a>.
</p></dd></dl>


<span id="XREFbin2dec"></span><dl class="def">
<dt id="index-bin2dec"><span class="category">: </span><span><em></em> <strong>bin2dec</strong> <em>(<var>s</var>)</em><a href='#index-bin2dec' class='copiable-anchor'> &para;</a></span></dt>
<dd><p>Return the decimal number corresponding to the binary number represented
by the string <var>s</var>.
</p>
<p>For example:
</p>
<div class="example">
<pre class="example">bin2dec (&quot;1110&quot;)
     &rArr; 14
</pre></div>

<p>Spaces are ignored during conversion and may be used to make the binary
number more readable.
</p>
<div class="example">
<pre class="example">bin2dec (&quot;1000 0001&quot;)
     &rArr; 129
</pre></div>

<p>If <var>s</var> is a string matrix, return a column vector with one converted
number per row of <var>s</var>; Invalid rows evaluate to NaN.
</p>
<p>If <var>s</var> is a cell array of strings, return a column vector with one
converted number per cell element in <var>s</var>.
</p>
<p><strong>See also:</strong> <a href="#XREFdec2bin">dec2bin</a>, <a href="#XREFbase2dec">base2dec</a>, <a href="#XREFhex2dec">hex2dec</a>.
</p></dd></dl>


<span id="XREFdec2bin"></span><dl class="def">
<dt id="index-dec2bin"><span class="category">: </span><span><em><var>bstr</var> =</em> <strong>dec2bin</strong> <em>(<var>d</var>)</em><a href='#index-dec2bin' class='copiable-anchor'> &para;</a></span></dt>
<dt id="index-dec2bin-1"><span class="category">: </span><span><em><var>bstr</var> =</em> <strong>dec2bin</strong> <em>(<var>d</var>, <var>len</var>)</em><a href='#index-dec2bin-1' class='copiable-anchor'> &para;</a></span></dt>
<dd><p>Return a string of ones and zeros representing the conversion of the integer
<var>d</var> to a binary number.
</p>
<p>If <var>d</var> is a matrix or cell array, return a string matrix with one row
for each element in <var>d</var>, padded with leading zeros to the width of the
largest value.
</p>
<p>The optional second argument, <var>len</var>, specifies the minimum number of
digits in the result.
</p>
<p>For negative elements of <var>d</var>, return the binary value of the two&rsquo;s
complement.  The result is padded with leading ones to 8, 16, 32, or 64
bits as appropriate for the magnitude of the input.  Positive input
elements are padded with leading zeros to the same width.  If the second
argument <var>len</var> exceeds that calculated width, the result is further
padded with leading zeros, for compatibility with <small>MATLAB</small>.
</p>
<p>Examples:
</p>
<div class="example">
<pre class="example">dec2bin (14)
     &rArr; &quot;1110&quot;

dec2bin (-14)
     &rArr; &quot;11110010&quot;
</pre></div>

<p>Known <small>MATLAB</small> Incompatibility: <small>MATLAB</small>&rsquo;s <code>dec2bin</code> allows
non-integer values for <var>d</var> as of Release 2022b, but is inconsistent
with truncation versus rounding and is also inconsistent with its own
<code>dec2hex</code> function.  For self-consistency, Octave gives an error for
non-integer inputs.  Users requiring compatible code for non-integer inputs
should make use of <code>fix</code> or <code>round</code> as appropriate.
</p>
<p><strong>See also:</strong> <a href="#XREFbin2dec">bin2dec</a>, <a href="#XREFdec2base">dec2base</a>, <a href="#XREFdec2hex">dec2hex</a>.
</p></dd></dl>


<span id="XREFdec2hex"></span><dl class="def">
<dt id="index-dec2hex"><span class="category">: </span><span><em><var>hstr</var> =</em> <strong>dec2hex</strong> <em>(<var>d</var>)</em><a href='#index-dec2hex' class='copiable-anchor'> &para;</a></span></dt>
<dt id="index-dec2hex-1"><span class="category">: </span><span><em><var>hstr</var> =</em> <strong>dec2hex</strong> <em>(<var>d</var>, <var>len</var>)</em><a href='#index-dec2hex-1' class='copiable-anchor'> &para;</a></span></dt>
<dd><p>Return a string representing the conversion of the integer <var>d</var> to a
hexadecimal (base16) number.
</p>
<p>If <var>d</var> is negative, return the hexadecimal equivalent of the two&rsquo;s
complement binary value of <var>d</var>.
If <var>d</var> is a matrix or cell array, return a string matrix with one row
for each element in <var>d</var>, padded with leading zeros to the width of the
largest value.
</p>
<p>The optional second argument, <var>len</var>, specifies the minimum number of
digits in the result.
</p>
<p>Examples:
</p>
<div class="example">
<pre class="example">dec2hex (2748)
     &rArr; &quot;ABC&quot;

dec2hex (-2)
     &rArr; &quot;FE&quot;
</pre></div>


<p><strong>See also:</strong> <a href="#XREFhex2dec">hex2dec</a>, <a href="#XREFdec2base">dec2base</a>, <a href="#XREFdec2bin">dec2bin</a>.
</p></dd></dl>


<span id="XREFhex2dec"></span><dl class="def">
<dt id="index-hex2dec"><span class="category">: </span><span><em></em> <strong>hex2dec</strong> <em>(<var>s</var>)</em><a href='#index-hex2dec' class='copiable-anchor'> &para;</a></span></dt>
<dd><p>Return the integer corresponding to the hexadecimal number represented by
the string <var>s</var>.
</p>
<p>For example:
</p>
<div class="example">
<pre class="example">hex2dec (&quot;12B&quot;)
      &rArr; 299
hex2dec (&quot;12b&quot;)
      &rArr; 299
</pre></div>

<p>If <var>s</var> is a string matrix, return a column vector with one converted
number per row of <var>s</var>; Invalid rows evaluate to NaN.
</p>
<p>If <var>s</var> is a cell array of strings, return a column vector with one
converted number per cell element in <var>s</var>.
</p>

<p><strong>See also:</strong> <a href="#XREFdec2hex">dec2hex</a>, <a href="#XREFbase2dec">base2dec</a>, <a href="#XREFbin2dec">bin2dec</a>.
</p></dd></dl>


<span id="XREFdec2base"></span><dl class="def">
<dt id="index-dec2base"><span class="category">: </span><span><em></em> <strong>dec2base</strong> <em>(<var>d</var>, <var>base</var>)</em><a href='#index-dec2base' class='copiable-anchor'> &para;</a></span></dt>
<dt id="index-dec2base-1"><span class="category">: </span><span><em></em> <strong>dec2base</strong> <em>(<var>d</var>, <var>base</var>, <var>len</var>)</em><a href='#index-dec2base-1' class='copiable-anchor'> &para;</a></span></dt>
<dd><p>Return a string of symbols in base <var>base</var> corresponding to the
non-negative integer <var>d</var>.
</p>
<div class="example">
<pre class="example">dec2base (123, 3)
   &rArr; &quot;11120&quot;
</pre></div>

<p>If <var>d</var> is a matrix or cell array, return a string matrix with one row
per element in <var>d</var>, padded with leading zeros to the width of the
largest value.
</p>
<p>If <var>base</var> is a string then the characters of <var>base</var> are used as
the symbols for the digits of <var>d</var>.  Whitespace (spaces, tabs, newlines,
, etc.) may not be used as a symbol.
</p>
<div class="example">
<pre class="example">dec2base (123, &quot;aei&quot;)
   &rArr; &quot;eeeia&quot;
</pre></div>

<p>The optional third argument, <var>len</var>, specifies the minimum number of
digits in the result.
</p>
<p><strong>See also:</strong> <a href="#XREFbase2dec">base2dec</a>, <a href="#XREFdec2bin">dec2bin</a>, <a href="#XREFdec2hex">dec2hex</a>.
</p></dd></dl>


<span id="XREFbase2dec"></span><dl class="def">
<dt id="index-base2dec"><span class="category">: </span><span><em></em> <strong>base2dec</strong> <em>(<var>s</var>, <var>base</var>)</em><a href='#index-base2dec' class='copiable-anchor'> &para;</a></span></dt>
<dd><p>Convert <var>s</var> from a string of digits in base <var>base</var> to a decimal
integer (base 10).
</p>
<div class="example">
<pre class="example">base2dec (&quot;11120&quot;, 3)
   &rArr; 123
</pre></div>

<p>If <var>s</var> is a string matrix, return a column vector with one value per
row of <var>s</var>.  If a row contains invalid symbols then the corresponding
value will be NaN.
</p>
<p>If <var>s</var> is a cell array of strings, return a column vector with one
value per cell element in <var>s</var>.
</p>
<p>If <var>base</var> is a string, the characters of <var>base</var> are used as the
symbols for the digits of <var>s</var>.  Space (&rsquo; &rsquo;) may not be used as a symbol.
</p>
<div class="example">
<pre class="example">base2dec (&quot;yyyzx&quot;, &quot;xyz&quot;)
   &rArr; 123
</pre></div>

<p><strong>See also:</strong> <a href="#XREFdec2base">dec2base</a>, <a href="#XREFbin2dec">bin2dec</a>, <a href="#XREFhex2dec">hex2dec</a>.
</p></dd></dl>


<span id="XREFnum2hex"></span><dl class="def">
<dt id="index-num2hex"><span class="category">: </span><span><em><var>s</var> =</em> <strong>num2hex</strong> <em>(<var>n</var>)</em><a href='#index-num2hex' class='copiable-anchor'> &para;</a></span></dt>
<dt id="index-num2hex-1"><span class="category">: </span><span><em><var>s</var> =</em> <strong>num2hex</strong> <em>(<var>n</var>, &quot;cell&quot;)</em><a href='#index-num2hex-1' class='copiable-anchor'> &para;</a></span></dt>
<dd><p>Convert a numeric array to an array of hexadecimal strings.
</p>
<p>For example:
</p>
<div class="example">
<pre class="example">num2hex ([-1, 1, e, Inf])
&rArr; &quot;bff0000000000000
    3ff0000000000000
    4005bf0a8b145769
    7ff0000000000000&quot;
</pre></div>

<p>If the argument <var>n</var> is a single precision number or vector, the returned
string has a length of 8.  For example:
</p>
<div class="example">
<pre class="example">num2hex (single ([-1, 1, e, Inf]))
&rArr; &quot;bf800000
    3f800000
    402df854
    7f800000&quot;
</pre></div>

<p>With the optional second argument <code>&quot;cell&quot;</code>, return a cell array of
strings instead of a character array.
</p>
<p><strong>See also:</strong> <a href="#XREFhex2num">hex2num</a>, <a href="#XREFhex2dec">hex2dec</a>, <a href="#XREFdec2hex">dec2hex</a>.
</p></dd></dl>


<span id="XREFhex2num"></span><dl class="def">
<dt id="index-hex2num"><span class="category">: </span><span><em><var>n</var> =</em> <strong>hex2num</strong> <em>(<var>s</var>)</em><a href='#index-hex2num' class='copiable-anchor'> &para;</a></span></dt>
<dt id="index-hex2num-1"><span class="category">: </span><span><em><var>n</var> =</em> <strong>hex2num</strong> <em>(<var>s</var>, <var>class</var>)</em><a href='#index-hex2num-1' class='copiable-anchor'> &para;</a></span></dt>
<dd><p>Typecast a hexadecimal character array or cell array of strings to an
array of numbers.
</p>
<p>By default, the input array is interpreted as a hexadecimal number
representing a double precision value.  If fewer than 16 characters are
given the strings are right padded with <code>'0'</code> characters.
</p>
<p>Given a string matrix, <code>hex2num</code> treats each row as a separate number.
</p>
<div class="example">
<pre class="example">hex2num ([&quot;4005bf0a8b145769&quot;; &quot;4024000000000000&quot;])
   &rArr; [2.7183; 10.000]
</pre></div>

<p>The optional second argument <var>class</var> may be used to cause the input
array to be interpreted as a different value type.  Possible values are
</p>
<table>
<thead><tr><th>Option</th><th>Characters</th></tr></thead>
<tr><td><code>&quot;int8&quot;</code></td><td>2</td></tr>
<tr><td><code>&quot;uint8&quot;</code></td><td>2</td></tr>
<tr><td><code>&quot;int16&quot;</code></td><td>4</td></tr>
<tr><td><code>&quot;uint16&quot;</code></td><td>4</td></tr>
<tr><td><code>&quot;int32&quot;</code></td><td>8</td></tr>
<tr><td><code>&quot;uint32&quot;</code></td><td>8</td></tr>
<tr><td><code>&quot;int64&quot;</code></td><td>16</td></tr>
<tr><td><code>&quot;uint64&quot;</code></td><td>16</td></tr>
<tr><td><code>&quot;char&quot;</code></td><td>2</td></tr>
<tr><td><code>&quot;single&quot;</code></td><td>8</td></tr>
<tr><td><code>&quot;double&quot;</code></td><td>16</td></tr>
</table>

<p>For example:
</p>
<div class="example">
<pre class="example">hex2num ([&quot;402df854&quot;; &quot;41200000&quot;], &quot;single&quot;)
   &rArr; [2.7183; 10.000]
</pre></div>

<p><strong>See also:</strong> <a href="#XREFnum2hex">num2hex</a>, <a href="#XREFhex2dec">hex2dec</a>, <a href="#XREFdec2hex">dec2hex</a>.
</p></dd></dl>


<span id="XREFstrread"></span><dl class="def">
<dt id="index-strread"><span class="category">: </span><span><em>[<var>a</var>, &hellip;] =</em> <strong>strread</strong> <em>(<var>str</var>)</em><a href='#index-strread' class='copiable-anchor'> &para;</a></span></dt>
<dt id="index-strread-1"><span class="category">: </span><span><em>[<var>a</var>, &hellip;] =</em> <strong>strread</strong> <em>(<var>str</var>, <var>format</var>)</em><a href='#index-strread-1' class='copiable-anchor'> &para;</a></span></dt>
<dt id="index-strread-2"><span class="category">: </span><span><em>[<var>a</var>, &hellip;] =</em> <strong>strread</strong> <em>(<var>str</var>, <var>format</var>, <var>format_repeat</var>)</em><a href='#index-strread-2' class='copiable-anchor'> &para;</a></span></dt>
<dt id="index-strread-3"><span class="category">: </span><span><em>[<var>a</var>, &hellip;] =</em> <strong>strread</strong> <em>(<var>str</var>, <var>format</var>, <var>prop1</var>, <var>value1</var>, &hellip;)</em><a href='#index-strread-3' class='copiable-anchor'> &para;</a></span></dt>
<dt id="index-strread-4"><span class="category">: </span><span><em>[<var>a</var>, &hellip;] =</em> <strong>strread</strong> <em>(<var>str</var>, <var>format</var>, <var>format_repeat</var>, <var>prop1</var>, <var>value1</var>, &hellip;)</em><a href='#index-strread-4' class='copiable-anchor'> &para;</a></span></dt>
<dd>
<p>This function is obsolete.  Use <code>textscan</code> instead.
</p>
<p>Read data from a string.
</p>
<p>The string <var>str</var> is split into words that are repeatedly matched to the
specifiers in <var>format</var>.  The first word is matched to the first
specifier, the second to the second specifier and so forth.  If there are
more words than specifiers, the process is repeated until all words have
been processed.
</p>
<p>The string <var>format</var> describes how the words in <var>str</var> should be
parsed.  It may contain any combination of the following specifiers:
</p>
<dl compact="compact">
<dt><span><code>%s</code></span></dt>
<dd><p>The word is parsed as a string.
</p>
</dd>
<dt><span><code>%f</code></span></dt>
<dt><span><code>%n</code></span></dt>
<dd><p>The word is parsed as a number and converted to double.
</p>
</dd>
<dt><span><code>%d</code></span></dt>
<dt><span><code>%u</code></span></dt>
<dd><p>The word is parsed as a number and converted to int32.
</p>
</dd>
<dt><span><code>%*</code></span></dt>
<dt><span><code>%*f</code></span></dt>
<dt><span><code>%*s</code></span></dt>
<dd><p>The word is skipped.
</p>
<p>For %s and %d, %f, %n, %u and the associated %*s &hellip; specifiers an
optional width can be specified as %Ns, etc. where N is an integer &gt; 1.
For %f, format specifiers like %N.Mf are allowed.
</p>
</dd>
<dt><span><code>literals</code></span></dt>
<dd><p>In addition the format may contain literal character strings; these will be
skipped during reading.
</p></dd>
</dl>

<p>Parsed word corresponding to the first specifier are returned in the first
output argument and likewise for the rest of the specifiers.
</p>
<p>By default, <var>format</var> is <tt>&quot;%f&quot;</tt>, meaning that numbers are read from
<var>str</var>.  This will do if <var>str</var> contains only numeric fields.
</p>
<p>For example, the string
</p>
<div class="example">
<pre class="example"><var>str</var> = &quot;\
Bunny Bugs   5.5\n\
Duck Daffy  -7.5e-5\n\
Penguin Tux   6&quot;
</pre></div>

<p>can be read using
</p>
<div class="example">
<pre class="example">[<var>a</var>, <var>b</var>, <var>c</var>] = strread (<var>str</var>, &quot;%s %s %f&quot;);
</pre></div>

<p>Optional numeric argument <var>format_repeat</var> can be used for limiting the
number of items read:
</p>
<dl compact="compact">
<dt><span>-1</span></dt>
<dd><p>(default) read all of the string until the end.
</p>
</dd>
<dt><span>N</span></dt>
<dd><p>Read N times <var>nargout</var> items.  0 (zero) is an acceptable value for
<var>format_repeat</var>.
</p></dd>
</dl>

<p>The behavior of <code>strread</code> can be changed via property-value pairs.  The
following properties are recognized:
</p>
<dl compact="compact">
<dt><span><code>&quot;commentstyle&quot;</code></span></dt>
<dd><p>Parts of <var>str</var> are considered comments and will be skipped.
<var>value</var> is the comment style and can be any of the following.
</p>
<ul>
<li> <code>&quot;shell&quot;</code>
Everything from <code>#</code> characters to the nearest end-of-line is skipped.

</li><li> <code>&quot;c&quot;</code>
Everything between <code>/*</code> and <code>*/</code> is skipped.

</li><li> <code>&quot;c++&quot;</code>
Everything from <code>//</code> characters to the nearest end-of-line is skipped.

</li><li> <code>&quot;matlab&quot;</code>
Everything from <code>%</code> characters to the nearest end-of-line is skipped.

</li><li> user-supplied.  Two options:
(1) One string, or 1x1 cell string: Skip everything to the right of it;
(2) 2x1 cell string array: Everything between the left and right strings
is skipped.
</li></ul>

</dd>
<dt><span><code>&quot;delimiter&quot;</code></span></dt>
<dd><p>Any character in <var>value</var> will be used to split <var>str</var> into words
(default value = any whitespace).  Note that whitespace is implicitly added
to the set of delimiter characters unless a <code>&quot;%s&quot;</code> format conversion
specifier is supplied; see <code>&quot;whitespace&quot;</code> parameter below.  The set
of delimiter characters cannot be empty; if needed Octave substitutes a
space as delimiter.
</p>
</dd>
<dt><span><code>&quot;emptyvalue&quot;</code></span></dt>
<dd><p>Value to return for empty numeric values in non-whitespace delimited data.
The default is NaN.  When the data type does not support NaN (int32 for
example), then default is zero.
</p>
</dd>
<dt><span><code>&quot;multipledelimsasone&quot;</code></span></dt>
<dd><p>Treat a series of consecutive delimiters, without whitespace in between,
as a single delimiter.  Consecutive delimiter series need not be vertically
<code>&quot;aligned&quot;</code>.
</p>
</dd>
<dt><span><code>&quot;treatasempty&quot;</code></span></dt>
<dd><p>Treat single occurrences (surrounded by delimiters or whitespace) of the
string(s) in <var>value</var> as missing values.
</p>
</dd>
<dt><span><code>&quot;returnonerror&quot;</code></span></dt>
<dd><p>If <var>value</var> true (1, default), ignore read errors and return normally.
If false (0), return an error.
</p>
</dd>
<dt><span><code>&quot;whitespace&quot;</code></span></dt>
<dd><p>Any character in <var>value</var> will be interpreted as whitespace and trimmed;
the string defining whitespace must be enclosed in double quotes for proper
processing of special characters like <code>&quot;\t&quot;</code>.  In
each data field, multiple consecutive whitespace characters are collapsed
into one space and leading and trailing whitespace is removed.  The default
value for whitespace is
<code>&quot;
\b\r\n\t&quot;</code>
(note the space).  Whitespace is always added to the set of delimiter
characters unless at least one <code>&quot;%s&quot;</code> format conversion specifier is
supplied; in that case only whitespace explicitly specified in
<code>&quot;delimiter&quot;</code> is retained as delimiter and removed from the set of
whitespace characters.  If whitespace characters are to be kept as-is (in
e.g., strings), specify an empty value (i.e., <code>&quot;&quot;</code>) for
<code>&quot;whitespace&quot;</code>; obviously, whitespace cannot be a delimiter then.
</p>
</dd>
</dl>

<p>When the number of words in <var>str</var> doesn&rsquo;t match an exact multiple of
the number of format conversion specifiers, strread&rsquo;s behavior depends on
the last character of <var>str</var>:
</p>
<dl compact="compact">
<dt><span>last character = <code>&quot;\n&quot;</code></span></dt>
<dd><p>Data columns are padded with empty fields or NaN so that all columns have
equal length
</p>
</dd>
<dt><span>last character is not <code>&quot;\n&quot;</code></span></dt>
<dd><p>Data columns are not padded; strread returns columns of unequal length
</p>
</dd>
</dl>


<p><strong>See also:</strong> <a href="Simple-File-I_002fO.html#XREFtextscan">textscan</a>, <a href="Formatted-Input.html#XREFsscanf">sscanf</a>.
</p></dd></dl>


</div>
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<p>
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