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Diffstat (limited to 'help/en_US/ellipord.xml')
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1 files changed, 1 insertions, 49 deletions
diff --git a/help/en_US/ellipord.xml b/help/en_US/ellipord.xml index 2a3dbe2..2b42f22 100644 --- a/help/en_US/ellipord.xml +++ b/help/en_US/ellipord.xml @@ -17,55 +17,7 @@ <refnamediv> <refname>ellipord</refname> - <refpurpose>Minimum filter order of a digital elliptic/Cauer filter with the desired response characteristics. </refpurpose> + <refpurpose>Minimum filter order of a digital elliptic or Cauer filter with the desired response characteristics.</refpurpose> </refnamediv> - -<refsynopsisdiv> - <title>Calling Sequence</title> - <synopsis> - n = ellipord(Wp, Ws, Rp, Rs) - [n, Wp] = ellipord(Wp, Ws, Rp, Rs) - </synopsis> -</refsynopsisdiv> - -<refsection> - <title>Parameters</title> - <variablelist> - <varlistentry><term>Wp:</term> - <listitem><para> scalar or vector of length 2 (passband edge(s)), all elements must be in the range [0,1]</para></listitem></varlistentry> - <varlistentry><term>Ws:</term> - <listitem><para> scalar or vector of length 2 (stopband edge(s)), all elements must be in the range [0,1]</para></listitem></varlistentry> - <varlistentry><term>Rp:</term> - <listitem><para> passband ripple in dB.</para></listitem></varlistentry> - <varlistentry><term>Rs:</term> - <listitem><para> stopband attenuation in dB.</para></listitem></varlistentry> - <varlistentry><term>n:</term> - <listitem><para> Minimum order of filter satisfying given specs.</para></listitem></varlistentry> - </variablelist> -</refsection> - -<refsection> - <title>Description</title> - <para> -This function computes the minimum filter order of an elliptic filter with the desired response characteristics.</para> -<para>Stopband frequency ws and passband frequency wp specify the the filter frequency band edges.</para> -<para>Frequencies are normalized to the Nyquist frequency in the range [0,1].</para> -<para>Rp is measured in decibels and is the allowable passband ripple and Rs is also measured in decibels and is the minimum attenuation in the stop band.</para> -<para>If ws>wp then the filter is a low pass filter. If wp>ws, then the filter is a high pass filter.</para> -<para>If wp and ws are vectors of length 2, then the passband interval is defined by wp and the stopband interval is defined by ws.</para> -<para>If wp is contained within the lower and upper limits of ws, the filter is a band-pass filter. If ws is contained within the lower and upper limits of wp, the filter is a band-stop or band-reject filter. -</para> -</refsection> - -<refsection> - <title>Examples</title> - <programlisting role="example"><![CDATA[ - Wp = [60 200]/500; - Ws = [50 250]/500; - Rp = 3; - Rs = 40; - [n,Wp] = ellipord(Wp,Ws,Rp,Rs) - ]]></programlisting> -</refsection> </refentry> |