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<?xml version="1.0" encoding="UTF-8"?>
<!--
*
* This help file was generated from besself.sci using help_from_sci().
*
-->
<refentry version="5.0-subset Scilab" xml:id="besself" xml:lang="en"
xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xmlns:svg="http://www.w3.org/2000/svg"
xmlns:ns3="http://www.w3.org/1999/xhtml"
xmlns:mml="http://www.w3.org/1998/Math/MathML"
xmlns:scilab="http://www.scilab.org"
xmlns:db="http://docbook.org/ns/docbook">
<refnamediv>
<refname>besself</refname>
<refpurpose>Bessel filter design.</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Calling Sequence</title>
<synopsis>
[b, a] = besself(n, Wc)
[b, a] = besself (n, Wc, "high")
[b, a] = besself (n, [Wl, Wh])
[b, a] = besself (n, [Wl, Wh], "stop")
[z, p, g] = besself (…)
[…] = besself (…, "z")
</synopsis>
</refsynopsisdiv>
<refsection>
<title>Parameters</title>
<variablelist>
<varlistentry><term>n:</term>
<listitem><para> positive integer value (order of filter)</para></listitem></varlistentry>
<varlistentry><term>W:</term>
<listitem><para> positive real value</para><para> 1).Analog 3dB cutoff frequency/frequencies for analog filter, in the range [0, Inf] {rad/sec}</para><para> 2).Normalised digital 3dB cutoff frequency/frequencies for digital filter, in the range [0, 1] {dimensionless}</para></listitem></varlistentry>
</variablelist>
</refsection>
<refsection>
<title>Description</title>
<para>
This function generates a Bessel filter. The default is a Laplace space (s) or analog filter.</para>
<para>If second argument is scalar the third parameter takes in high or low, the default value being low. The cutoff is Wc rad/sec.</para>
<para>If second argument is vector of length 2 ie [Wl Wh] then third parameter may be pass or stop default is pass for bandpass and band reject filter respectively</para>
<para>[z,p,g] = besself(...) returns filter as zero-pole-gain rather than coefficients of the numerator and denominator polynomials.</para>
<para>[...] = besself(...,’z’) returns a discrete space (Z) filter. Wc must be less than 1 {dimensionless}.
</para>
</refsection>
<refsection>
<title>Examples</title>
<programlisting role="example"><![CDATA[
n = 2;
wc = 0.3;
[b, a]=besself(n, wc, "high", "z")
]]></programlisting>
</refsection>
</refentry>
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