<?xml version="1.0" encoding="ISO-8859-1" standalone="no"?>
<!DOCTYPE MAN SYSTEM "../../manrev.dtd">
<MAN>
  <LANGUAGE>eng</LANGUAGE>
  <TITLE>cepstrum</TITLE>
  <TYPE>Scilab Function</TYPE>
  <DATE>April 1993</DATE>
  <SHORT_DESCRIPTION name="cepstrum"> cepstrum calculation</SHORT_DESCRIPTION>
  <CALLING_SEQUENCE>
    <CALLING_SEQUENCE_ITEM>fresp = cepstrum(w,mag)  </CALLING_SEQUENCE_ITEM>
  </CALLING_SEQUENCE>
  <PARAM>
    <PARAM_INDENT>
      <PARAM_ITEM>
        <PARAM_NAME>w</PARAM_NAME>
        <PARAM_DESCRIPTION>
          <SP>: positive real vector of frequencies (rad/sec)</SP>
        </PARAM_DESCRIPTION>
      </PARAM_ITEM>
      <PARAM_ITEM>
        <PARAM_NAME>mag</PARAM_NAME>
        <PARAM_DESCRIPTION>
          <SP>: real vector of magnitudes (same size as <VERB>w</VERB>)</SP>
        </PARAM_DESCRIPTION>
      </PARAM_ITEM>
      <PARAM_ITEM>
        <PARAM_NAME>fresp</PARAM_NAME>
        <PARAM_DESCRIPTION>
          <SP>: complex vector</SP>
        </PARAM_DESCRIPTION>
      </PARAM_ITEM>
    </PARAM_INDENT>
  </PARAM>
  <DESCRIPTION>
    <P><VERB>fresp = cepstrum(w,mag)</VERB> returns a frequency response <VERB>fresp(i)</VERB>
    whose magnitude at frequency <VERB>w(i)</VERB> equals <VERB>mag(i)</VERB>  and such
    that the phase of <VERB>freq</VERB> corresponds to a stable and minimum phase
    system. <VERB>w</VERB> needs not to be sorted, but  minimal entry should not be
    close to zero and all the entries of <VERB>w</VERB> should be different.</P>
  </DESCRIPTION>
  <EXAMPLE>
<![CDATA[
w=0.1:0.1:5;mag=1+abs(sin(w));
fresp=cepstrum(w,mag);
plot2d([w',w'],[mag(:),abs(fresp)])
 ]]>
  </EXAMPLE>
  <SEE_ALSO>
    <SEE_ALSO_ITEM>
      <LINK>frfit</LINK>
    </SEE_ALSO_ITEM>
  </SEE_ALSO>
</MAN>
