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Diffstat (limited to 'help/en_US/ellip.xml')
| -rw-r--r-- | help/en_US/ellip.xml | 48 |
1 files changed, 23 insertions, 25 deletions
diff --git a/help/en_US/ellip.xml b/help/en_US/ellip.xml index 847f91e..66ec6fc 100644 --- a/help/en_US/ellip.xml +++ b/help/en_US/ellip.xml @@ -17,20 +17,19 @@ <refnamediv> <refname>ellip</refname> - <refpurpose>This function generates an elliptic or Cauer filter with rp dB of passband ripple and rs dB of stopband attenuation.</refpurpose> + <refpurpose>Elliptic/Cauer filter design with rp dB of passband ripple and rs dB of stopband attenuation.</refpurpose> </refnamediv> <refsynopsisdiv> <title>Calling Sequence</title> <synopsis> - [a, b] = ellip (n, rp, rs, wp) - [a, b] = ellip (n, rp, rs, wp, "high") - [a, b] = ellip (n, rp, rs, [wl, wh]) - [a, b] = ellip (n, rp, rs, [wl, wh], "stop") - [a, b, c] = ellip (…) - [a, b, c, d] = ellip (…) - […] = ellip (…, "s") + [b, a] = ellip (n, rp, rs, wp) + [b, a] = ellip (n, rp, rs, wp, "high") + [b, a] = ellip (n, rp, rs, [wl, wh]) + [b, a] = ellip (n, rp, rs, [wl, wh], "stop") + [z, p, g] = ellip (…) + […] = ellip (…, "s") </synopsis> </refsynopsisdiv> @@ -38,37 +37,36 @@ <title>Parameters</title> <variablelist> <varlistentry><term>n:</term> - <listitem><para> positive integer value</para></listitem></varlistentry> + <listitem><para> positive integer value (order of filter)</para></listitem></varlistentry> <varlistentry><term>rp:</term> - <listitem><para> non negative scalar value</para></listitem></varlistentry> + <listitem><para> non negative scalar value (passband ripple)</para></listitem></varlistentry> <varlistentry><term>rs:</term> - <listitem><para> non negative scalar value</para></listitem></varlistentry> - <varlistentry><term>w:</term> - <listitem><para> scalar or vector, all elements should be in the range [0,1]</para></listitem></varlistentry> + <listitem><para> non negative scalar value (stopband attenuation)</para></listitem></varlistentry> + <varlistentry><term>ws:</term> + <listitem><para> scalar or vector of length 2, all elements should be in the range [0,1]</para><para> 1).Normalised digital passband edge(s) for digital filter, in the range [0, 1] {dimensionless}</para><para> 2).Analog passband edge(s) for analog filter, in the range [0, Inf] {rad/sec}</para></listitem></varlistentry> </variablelist> </refsection> <refsection> <title>Description</title> <para> -This is an Octave function. -This function generates an elliptic or Cauer filter with rp dB of passband ripple and rs dB of stopband attenuation. -[b, a] = ellip(n, Rp, Rs, Wp) indicates low pass filter with order n, Rp decibels of ripple in the passband and a stopband Rs decibels down and cutoff of pi*Wp radians. If the fifth argument is high, then the filter is a high pass filter. -[b, a] = ellip(n, Rp, Rs, [Wl, Wh]) indictaes band pass filter with band pass edges pi*Wl and pi*Wh. If the fifth argument is stop, the filter is a band reject filter. -[z, p, g] = ellip(...) returns filter as zero-pole-gain. -[...] = ellip(...,’s’) returns a Laplace space filter, w can be larger than 1. -[a, b, c, d] = ellip(...) returns state-space matrices. +This function generates an elliptic or Cauer filter with rp dB of passband ripple and rs dB of stopband attenuation.</para> +<para>[b, a] = ellip(n, Rp, Rs, Wp) indicates low pass filter with order n, Rp decibels of ripple in the passband and a stopband Rs decibels down and cutoff of pi*Wp radians. If the fifth argument is high, then the filter is a high pass filter.</para> +<para>[b, a] = ellip(n, Rp, Rs, [Wl, Wh]) indictaes band pass filter with band pass edges pi*Wl and pi*Wh. If the fifth argument is stop, the filter is a band reject filter.</para> +<para>[b,a] = ellip(n, Rp, Rs, [Wl, Wh], 'stop') band reject filter with edges pi*Wl and pi*Wh</para> +<para>[z, p, g] = ellip(...) returns filter as zero-pole-gain.</para> +<para>[...] = ellip(...,’s’) returns a Laplace space filter, wp can be larger than 1 rad/sec. </para> </refsection> <refsection> <title>Examples</title> <programlisting role="example"><![CDATA[ -[a,b]=ellip(2, 0.5, 0.7, [0.3,0.4]) -a = -0.88532 -1.58410 2.40380 -1.58410 0.88532 -b = -1.00000 -1.78065 2.68703 -1.75725 0.97454 +n = 2; +rp = 3; +rs = 40; +wp = [0.3 0.4]; +[b, a]=ellip(n, rp, rs, wp) ]]></programlisting> </refsection> </refentry> |