code changes by Sonu Sharma during FOSSEE Fellowship 2018

1 files changed, 31 insertions, 27 deletions

diff --git a/help/en_US/cheby2.xml b/help/en_US/cheby2.xml
index 24cef7d..7eb4fea 100644
--- a/help/en_US/cheby2.xml
+++ b/help/en_US/cheby2.xml
@@ -17,20 +17,19 @@
 
   <refnamediv>
     <refname>cheby2</refname>
-    <refpurpose>This function generates a Chebyshev type II filter with rs dB of stopband attenuation.</refpurpose>
+    <refpurpose>Chebyshev type II filter design with rs dB of stopband attenuation.</refpurpose>
   </refnamediv>
 
 
 <refsynopsisdiv>
    <title>Calling Sequence</title>
    <synopsis>
-   [a, b] = cheby2 (n, rs, wc)
-   [a, b] = cheby2 (n, rs, wc, "high")
-   [a, b] = cheby2 (n, rs, [wl, wh])
-   [a, b] = cheby2 (n, rs, [wl, wh], "stop")
-   [a, b, c] = cheby2 (…)
-   [a, b, c, d] = cheby2 (…)
-   […] = cheby2 (…, "s")
+    [b, a] = cheby2 (n, rs, ws)
+    [b, a] = cheby2 (n, rs, ws, "high")
+    [b, a] = cheby2 (n, rs, [wl, wh])
+    [b, a] = cheby2 (n, rs, [wl, wh], "stop")
+    [z, p, g] = cheby2 (…)
+    […] = cheby2 (…, "s")
    </synopsis>
 </refsynopsisdiv>
 
@@ -38,37 +37,42 @@
    <title>Parameters</title>
    <variablelist>
    <varlistentry><term>n:</term>
-      <listitem><para> positive integer value</para></listitem></varlistentry>
-   <varlistentry><term>rp:</term>
-      <listitem><para> non negative scalar value</para></listitem></varlistentry>
-   <varlistentry><term>w:</term>
-      <listitem><para> vector, all elements must be in the range [0,1]</para></listitem></varlistentry>
+      <listitem><para> positive integer value (order of filter)</para></listitem></varlistentry>
+   <varlistentry><term>rs:</term>
+      <listitem><para> non negative scalar value (stopband attenuation in dB)</para></listitem></varlistentry>
+   <varlistentry><term>ws:</term>
+      <listitem><para> vector, all elements must be in the range [0,1]</para><para>    1).Normalised digital stopband edge(s) for digital filter, in the range [0, 1] {dimensionless}</para><para>    2).Analog stopband 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 a Chebyshev type II filter with rs dB of stopband attenuation.
-The fourth parameter takes in high or low, default value is low. The cutoff is pi*Wc radians.
-[b, a] = cheby2(n, Rp, [Wl, Wh]) indicates a band pass filter with edges pi*Wl and pi*Wh radians.
-[b, a] = cheby2(n, Rp, [Wl, Wh], ’stop’) indicates a band reject filter with edges pi*Wl and pi*Wh radians.
-[z, p, g] = cheby2(...) returns filter as zero-pole-gain rather than coefficients of the numerator and denominator polynomials.
-[...] = cheby2(...,’s’) returns a Laplace space filter, w can be larger than 1.
-[a,b,c,d] = cheby2(...) returns state-space matrices.
+This function generates a Chebyshev type II filter with rs dB of stopband attenuation.</para>
+<para>If third parameter is scalar then,the fourth parameter takes in high or low, default value is low. The cutoff is pi*Wc radians.</para>
+<para>[b, a] = cheby2(n, Rp, [Wl, Wh]) indicates a band pass filter with edges pi*Wl and pi*Wh radians.</para>
+<para>[b, a] = cheby2(n, Rp, [Wl, Wh], ’stop’) indicates a band reject filter with edges pi*Wl and pi*Wh radians.</para>
+<para>[z, p, g] = cheby2(...) returns filter as zero-pole-gain rather than coefficients of the numerator and denominator polynomials.</para>
+<para>[...] = cheby2(...,’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,c]=cheby2(2,5,0.7,"high")
-a =
--0.31645 - 0.94861i  -0.31645 + 0.94861i
-b =
--0.39388 + 0.53138i  -0.39388 - 0.53138i
-c =  0.47528
+n = 2;
+rs = 5;
+ws = 0.7;
+[z, p, g]=cheby2(n, rs, ws, "high")
+
    ]]></programlisting>
 </refsection>
+
+<refsection>
+<title>Modified by :</title>
+<simplelist type="vert">
+<member>Sonu Sharma, RGIT Mumbai (fellow at FOSSEE, IIT Bombay)</member>
+    </simplelist>
+</refsection>
+
 </refentry>