<?xml version="1.0" encoding="ISO-8859-1" standalone="no"?>
<!DOCTYPE MAN SYSTEM "../../manrev.dtd">
<MAN>
  <LANGUAGE>eng</LANGUAGE>
  <TITLE>trans</TITLE>
  <TYPE>Scilab Function</TYPE>
  <DATE>April 1993</DATE>
  <SHORT_DESCRIPTION name="trans"> low-pass to other filter transform</SHORT_DESCRIPTION>
  <CALLING_SEQUENCE>
    <CALLING_SEQUENCE_ITEM>hzt=trans(hz,tr_type,frq)  </CALLING_SEQUENCE_ITEM>
    <CALLING_SEQUENCE_ITEM>hzt=trans(pd,zd,gd,tr_type,frq)  </CALLING_SEQUENCE_ITEM>
  </CALLING_SEQUENCE>
  <PARAM>
    <PARAM_INDENT>
      <PARAM_ITEM>
        <PARAM_NAME>hz</PARAM_NAME>
        <PARAM_DESCRIPTION>
          <SP>: given fiter transfert function</SP>
        </PARAM_DESCRIPTION>
      </PARAM_ITEM>
  
      <PARAM_ITEM>
        <PARAM_NAME>pd</PARAM_NAME>
        <PARAM_DESCRIPTION>
          <SP>: Vector of given fiter poles</SP>
        </PARAM_DESCRIPTION>
      </PARAM_ITEM>
      <PARAM_ITEM>
        <PARAM_NAME>zd</PARAM_NAME>
        <PARAM_DESCRIPTION>
          <SP>: Vector of given fiter zeros</SP>
        </PARAM_DESCRIPTION>
      </PARAM_ITEM>
      <PARAM_ITEM>
        <PARAM_NAME>gd</PARAM_NAME>
        <PARAM_DESCRIPTION>
          <SP>: scalar: the given fiter gain</SP>
        </PARAM_DESCRIPTION>
      </PARAM_ITEM>
      <PARAM_ITEM>
        <PARAM_NAME>tr_type</PARAM_NAME>
        <PARAM_DESCRIPTION>
          <SP>: string, the type of transformation, see description for possible values </SP>
        </PARAM_DESCRIPTION>
      </PARAM_ITEM>
      <PARAM_ITEM>
        <PARAM_NAME>frq</PARAM_NAME>
        <PARAM_DESCRIPTION>
          <SP>: 2-vector of discrete cut-off frequencies (i.e.,<VERB>0&lt;frq&lt;.5</VERB>). For lp and hp filters only frq(1) is used. For bp and sb filters frq(1) is the lower cut-off frequency and frq(2) is the upper cut-off frequency. </SP>
        </PARAM_DESCRIPTION>
      </PARAM_ITEM>
      <PARAM_ITEM>
        <PARAM_NAME>hzt</PARAM_NAME>
        <PARAM_DESCRIPTION>
          <SP>: transformed filter transfert function.</SP>
        </PARAM_DESCRIPTION>
      </PARAM_ITEM>
    </PARAM_INDENT>
  </PARAM>
  <DESCRIPTION>
    <P>
    function for transforming standardized low-pass filter given its
      poles-zeros_gain representation into
    one of the following filters:
    </P>
    <P>
      low-pass ('lp'), the cutoff frequency is given by the first entry of frq,
      the second one is ignored
    </P>
    <P>
      high-pass ('hp'),  the cutoff frequency is given by the first entry of frq,
      the second one is ignored
    </P>
    <P>
      
      band-pass ('bp'), the frequency range is given by frq(1) and frq(2)
    </P>
    <P>
      stop-band ('sb') , the frequency range is given by frq(1) and frq(2).
    </P>
  </DESCRIPTION>
  <EXAMPLE>
<![CDATA[
clf()

Hlp=iir(3,'lp','ellip',[0.1 0],[.08 .03]);
subplot(311)
gainplot(Hlp,1d-3,0.48)
legend('original low pass')


Hbp=trans(Hlp,'bp',[0.01 0.1]);
subplot(312)
gainplot(Hbp,1d-3,0.48)
legend('band pass')


Hsb=trans(Hlp,'sb',[0.01 0.1])
subplot(313)
gainplot(Hsb,1d-3,0.48)
legend('stop band')


 ]]>
  </EXAMPLE>
  <AUTHOR>C. Bunks ;   </AUTHOR>
</MAN>
