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<div class="title">FORMAT Control the Format of Matrix Display </div> </div>
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<div class="textblock"><p>Section: <a class="el" href="sec_io.html">Input/Ouput Functions</a> </p>
<h1><a class="anchor" id="Usage"></a>
Usage</h1>
<p>FreeMat supports several modes for displaying matrices (either through the <code>disp</code> function or simply by entering expressions on the command line. There are several options for the format command. The default mode is equivalent to </p>
<pre class="fragment"> format short
</pre><p> which generally displays matrices with 4 decimals, and scales matrices if the entries have magnitudes larger than roughly <code>1e2</code> or smaller than <code>1e-2</code>. For more information you can use </p>
<pre class="fragment"> format long
</pre><p> which displays roughly 7 decimals for <code>float</code> and <code>complex</code> arrays, and 14 decimals for <code>double</code> and <code>dcomplex</code>. You can also use </p>
<pre class="fragment"> format short e
</pre><p> to get exponential format with 4 decimals. Matrices are not scaled for exponential formats. Similarly, you can use </p>
<pre class="fragment"> format long e
</pre><p> which displays the same decimals as <code>format long</code>, but in exponential format. You can also use the <code>format</code> command to retrieve the current format: </p>
<pre class="fragment"> s = format
</pre><p> where <code>s</code> is a string describing the current format. </p>
<h1><a class="anchor" id="Example"></a>
Example</h1>
<p>We start with the short format, and two matrices, one of double precision, and the other of single precision.</p>
<pre class="fragment">--> format short
--> a = randn(4)
a =
-0.3756 0.0920 0.9516 1.8527
0.5078 -0.2088 -0.3120 -0.2380
0.5578 0.7695 0.0226 2.9326
-0.4420 -0.4871 -0.7582 -0.5059
--> b = float(randn(4))
b =
0.2010 0.3416 0.1562 -0.5460
1.2842 -0.3808 -1.2720 -0.3398
-0.7660 -0.6251 2.4811 0.7956
-0.1727 0.8577 1.5701 -1.5048
</pre><p>Note that in the short format, these two matrices are displayed with the same format. In <code>long</code> format, however, they display differently</p>
<pre class="fragment">--> format long
--> a
ans =
Columns 1 to 3
-0.37559630424227 0.09196341864118 0.95155934364300
0.50776589164635 -0.20877480315311 -0.31198760445638
0.55783547335483 0.76954243414671 0.02264031516947
-0.44202929771190 -0.48708606879623 -0.75822963661106
Columns 4 to 4
1.85265231634028
-0.23799081322695
2.93263318869123
-0.50590405332950
--> b
ans =
0.2010476 0.3415550 0.1561587 -0.5460028
1.2841575 -0.3808453 -1.2719837 -0.3397521
-0.7659672 -0.6251388 2.4811494 0.7956446
-0.1726678 0.8576548 1.5701485 -1.5048176
</pre><p>Note also that we we scale the contents of the matrices, FreeMat rescales the entries with a scale premultiplier.</p>
<pre class="fragment">--> format short
--> a*1e4
ans =
1.0e+04 *
-0.3756 0.0920 0.9516 1.8527
0.5078 -0.2088 -0.3120 -0.2380
0.5578 0.7695 0.0226 2.9326
-0.4420 -0.4871 -0.7582 -0.5059
--> a*1e-4
ans =
1.0e-04 *
-0.3756 0.0920 0.9516 1.8527
0.5078 -0.2088 -0.3120 -0.2380
0.5578 0.7695 0.0226 2.9326
-0.4420 -0.4871 -0.7582 -0.5059
--> b*1e4
ans =
1.0e+04 *
0.2010 0.3416 0.1562 -0.5460
1.2842 -0.3808 -1.2720 -0.3398
-0.7660 -0.6251 2.4811 0.7956
-0.1727 0.8577 1.5701 -1.5048
--> b*1e-4
ans =
1.0e-04 *
0.2010 0.3416 0.1562 -0.5460
1.2842 -0.3808 -1.2720 -0.3398
-0.7660 -0.6251 2.4811 0.7956
-0.1727 0.8577 1.5701 -1.5048
</pre><p>Next, we use the exponential formats:</p>
<pre class="fragment">--> format short e
--> a*1e4
ans =
-3.7560e+03 9.1963e+02 9.5156e+03 1.8527e+04
5.0777e+03 -2.0877e+03 -3.1199e+03 -2.3799e+03
5.5784e+03 7.6954e+03 2.2640e+02 2.9326e+04
-4.4203e+03 -4.8709e+03 -7.5823e+03 -5.0590e+03
--> a*1e-4
ans =
-3.7560e-05 9.1963e-06 9.5156e-05 1.8527e-04
5.0777e-05 -2.0877e-05 -3.1199e-05 -2.3799e-05
5.5784e-05 7.6954e-05 2.2640e-06 2.9326e-04
-4.4203e-05 -4.8709e-05 -7.5823e-05 -5.0590e-05
--> b*1e4
ans =
2.0105e+03 3.4156e+03 1.5616e+03 -5.4600e+03
1.2842e+04 -3.8085e+03 -1.2720e+04 -3.3975e+03
-7.6597e+03 -6.2514e+03 2.4811e+04 7.9564e+03
-1.7267e+03 8.5765e+03 1.5701e+04 -1.5048e+04
--> b*1e-4
ans =
2.0105e-05 3.4155e-05 1.5616e-05 -5.4600e-05
1.2842e-04 -3.8085e-05 -1.2720e-04 -3.3975e-05
-7.6597e-05 -6.2514e-05 2.4811e-04 7.9564e-05
-1.7267e-05 8.5765e-05 1.5701e-04 -1.5048e-04
</pre><p>Finally, if we assign the <code>format</code> function to a variable, we can retrieve the current format:</p>
<pre class="fragment">--> format short
--> t = format
t =
short
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