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<!DOCTYPE MAN SYSTEM "../../manrev.dtd">
<MAN>
  <LANGUAGE>eng</LANGUAGE>
  <TITLE>abcd</TITLE>
  <TYPE>Scilab Function</TYPE>
  <DATE>April 1993</DATE>
  <SHORT_DESCRIPTION name="abcd"> state-space matrices</SHORT_DESCRIPTION>
  <CALLING_SEQUENCE>
    <CALLING_SEQUENCE_ITEM>[A,B,C,D]=abcd(sl)  </CALLING_SEQUENCE_ITEM>
  </CALLING_SEQUENCE>
  <PARAM>
    <PARAM_INDENT>
      <PARAM_ITEM>
        <PARAM_NAME>sl</PARAM_NAME>
        <PARAM_DESCRIPTION>
          <SP>: linear system (<VERB>syslin</VERB> list) in state-space or transfer form</SP>
        </PARAM_DESCRIPTION>
      </PARAM_ITEM>
      <PARAM_ITEM>
        <PARAM_NAME>A,B,C,D</PARAM_NAME>
        <PARAM_DESCRIPTION>
          <SP>: real matrices of appropriate dimensions</SP>
        </PARAM_DESCRIPTION>
      </PARAM_ITEM>
    </PARAM_INDENT>
  </PARAM>
  <DESCRIPTION>
    <P>
    returns the <VERB>A,B,C,D</VERB> matrices from a linear system <VERB>Sl</VERB>.</P>
    <P>
    Utility function. For transfer matrices <VERB>Sl</VERB> is converted
    into state-space form by <VERB>tf2ss</VERB>.</P>
    <P>
    The matrices <VERB>A,B,C,D</VERB> are the elements <VERB>2</VERB> to <VERB>5</VERB> of
    the <VERB>syslin</VERB> list <VERB>Sl</VERB>, i.e. <VERB>[A,B,C,D] = Sl(2:5)</VERB> .</P>
  </DESCRIPTION>
  <EXAMPLE>
<![CDATA[
A=diag([1,2,3]);B=[1;1;1];C=[2,2,2];
sys=syslin('c',A,B,C);
sys("A")
sys("C")
[A1,B1,C1,D1]=abcd(sys);
A1
systf=ss2tf(sys);
[a,b,c,d]=abcd(systf)
spec(a)
c*b-C*B
c*a*b-C*A*B
 ]]>
  </EXAMPLE>
  <SEE_ALSO>
    <SEE_ALSO_ITEM>
      <LINK>syslin</LINK>
    </SEE_ALSO_ITEM>
    <SEE_ALSO_ITEM>
      <LINK>ssrand</LINK>
    </SEE_ALSO_ITEM>
  </SEE_ALSO>
</MAN>
