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<span id="Converting-Numerical-Data-to-Strings"></span><div class="header">
<p>
Previous: <a href="Concatenating-Strings.html" accesskey="p" rel="prev">Concatenating Strings</a>, Up: <a href="Creating-Strings.html" accesskey="u" rel="up">Creating Strings</a> [<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>
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<hr>
<span id="Converting-Numerical-Data-to-Strings-1"></span><h4 class="subsection">5.3.2 Converting Numerical Data to 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>
<dt id="index-mat2str">: <em><var>s</var> =</em> <strong>mat2str</strong> <em>(<var>x</var>, <var>n</var>)</em></dt>
<dt id="index-mat2str-1">: <em><var>s</var> =</em> <strong>mat2str</strong> <em>(<var>x</var>, <var>n</var>, "class")</em></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>"class"</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])
⇒ "[-0.3333+0.14i;0.3333-0.14i]"
mat2str ([ -1/3 +i/7; 1/3 -i/7 ], [4 2])
⇒ "[-0.3333+0i 0+0.14i;0.3333+0i -0-0.14i]"
mat2str (int16 ([1 -1]), "class")
⇒ "int16([1 -1])"
mat2str (logical (eye (2)))
⇒ "[true false;false true]"
isequal (x, eval (mat2str (x)))
⇒ 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>
<dt id="index-num2str">: <em></em> <strong>num2str</strong> <em>(<var>x</var>)</em></dt>
<dt id="index-num2str-1">: <em></em> <strong>num2str</strong> <em>(<var>x</var>, <var>precision</var>)</em></dt>
<dt id="index-num2str-2">: <em></em> <strong>num2str</strong> <em>(<var>x</var>, <var>format</var>)</em></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)
⇒ 123.456
num2str (123.456, 4)
⇒ 123.5
s = num2str ([1, 1.34; 3, 3.56], "%5.1f")
⇒ s =
1.0 1.3
3.0 3.6
whos s
⇒ 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)
⇒ 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>
<dt id="index-int2str">: <em></em> <strong>int2str</strong> <em>(<var>n</var>)</em></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)
⇒ 123
s = int2str ([1, 2, 3; 4, 5, 6])
⇒ s =
1 2 3
4 5 6
whos s
⇒ 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>
<hr>
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Previous: <a href="Concatenating-Strings.html" accesskey="p" rel="prev">Concatenating Strings</a>, Up: <a href="Creating-Strings.html" accesskey="u" rel="up">Creating Strings</a> [<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>
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