<?xml version="1.0" encoding="ISO-8859-1" standalone="no"?>
<!DOCTYPE MAN SYSTEM "../../manrev.dtd">
<MAN>
  <LANGUAGE>eng</LANGUAGE>
  <TITLE>sgrid</TITLE>
  <TYPE>Scilab Function</TYPE>
  <DATE>Jun 1997</DATE>
  <SHORT_DESCRIPTION name="sgrid"> s-plane grid lines.  </SHORT_DESCRIPTION>
  <CALLING_SEQUENCE>
    <CALLING_SEQUENCE_ITEM>sgrid()  </CALLING_SEQUENCE_ITEM>
    <CALLING_SEQUENCE_ITEM>sgrid('new')  </CALLING_SEQUENCE_ITEM>
    <CALLING_SEQUENCE_ITEM>sgrid(zeta,wn [,color])  </CALLING_SEQUENCE_ITEM>
  </CALLING_SEQUENCE>
  <DESCRIPTION>
    <P>
    Used in conjonction with evans, 
    plots lines of constant damping ratio (<VERB>zeta</VERB>)
    and natural frequency (<VERB>wn</VERB>).
  </P>
    <DESCRIPTION_INDENT>
      <DESCRIPTION_ITEM label="sgrid()">
        <SP>: add a grid over an existing continuous s-plane root with default values for <VERB>zeta</VERB> and <VERB>wn</VERB>.</SP>
      </DESCRIPTION_ITEM>
      <DESCRIPTION_ITEM label="sgrid('new')">
        <SP>: clears the graphic screen and then plots a default  s-plane grid</SP>
      </DESCRIPTION_ITEM>
      <DESCRIPTION_ITEM label="sgrid(zeta,wn [,color])">
        <SP>: same as <VERB>sgrid()</VERB> but uses the provided damping ratio and  natural frequency.</SP>
      </DESCRIPTION_ITEM>
    </DESCRIPTION_INDENT>
  </DESCRIPTION>
  <EXAMPLE>
<![CDATA[
H=syslin('c',352*poly(-5,'s')/poly([0,0,2000,200,25,1],'s','c'));
evans(H,100)
sgrid()
sgrid(0.6,2,7)
 ]]>
  </EXAMPLE>
  <SEE_ALSO>
    <SEE_ALSO_ITEM>
      <LINK>evans</LINK>
    </SEE_ALSO_ITEM>
  </SEE_ALSO>
</MAN>
