<?xml version="1.0" encoding="ISO-8859-1" standalone="no"?>
<!DOCTYPE MAN SYSTEM "../../manrev.dtd">
<MAN>
  <LANGUAGE>eng</LANGUAGE>
  <TITLE>p_margin</TITLE>
  <TYPE>Scilab Function</TYPE>
  <DATE>April 1993</DATE>
  <SHORT_DESCRIPTION name="p_margin"> phase margin</SHORT_DESCRIPTION>
  <CALLING_SEQUENCE>
    <CALLING_SEQUENCE_ITEM>[phm,fr]=p_margin(h)  </CALLING_SEQUENCE_ITEM>
    <CALLING_SEQUENCE_ITEM>phm=p_margin(h)  </CALLING_SEQUENCE_ITEM>
  </CALLING_SEQUENCE>
  <PARAM>
    <PARAM_INDENT>
      <PARAM_ITEM>
        <PARAM_NAME>h</PARAM_NAME>
        <PARAM_DESCRIPTION>
          <SP>: SISO linear system (<VERB>syslin</VERB> list).</SP>
        </PARAM_DESCRIPTION>
      </PARAM_ITEM>
      <PARAM_ITEM>
        <PARAM_NAME>phm</PARAM_NAME>
        <PARAM_DESCRIPTION>
          <SP>: phase margin (in degree)</SP>
        </PARAM_DESCRIPTION>
      </PARAM_ITEM>
      <PARAM_ITEM>
        <PARAM_NAME>fr</PARAM_NAME>
        <PARAM_DESCRIPTION>
          <SP>: corresponding frequency (hz)</SP>
        </PARAM_DESCRIPTION>
      </PARAM_ITEM>
    </PARAM_INDENT>
  </PARAM>
  <DESCRIPTION>
    <P>
    The phase margin is the values of the phase at points where the
    nyquist plot of <VERB>h</VERB> crosses the unit circle.</P>
  </DESCRIPTION>
  <EXAMPLE>
<![CDATA[
h=syslin('c',-1+%s,3+2*%s+%s^2)
[p,fr]=p_margin(h)  
[p,fr]=p_margin(h+0.7)  
nyquist(h+0.7)
t=(0:0.1:2*%pi)';plot2d(sin(t),cos(t),-3,'000')
 ]]>
  </EXAMPLE>
  <SEE_ALSO>
    <SEE_ALSO_ITEM>
      <LINK>chart</LINK>
    </SEE_ALSO_ITEM>
    <SEE_ALSO_ITEM>
      <LINK>black</LINK>
    </SEE_ALSO_ITEM>
    <SEE_ALSO_ITEM>
      <LINK>g_margin</LINK>
    </SEE_ALSO_ITEM>
    <SEE_ALSO_ITEM>
      <LINK>nyquist</LINK>
    </SEE_ALSO_ITEM>
  </SEE_ALSO>
  <AUTHOR>S. S.  </AUTHOR>
</MAN>
