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<!DOCTYPE MAN SYSTEM "../../manrev.dtd">
<MAN>
  <LANGUAGE>eng</LANGUAGE>
  <TITLE>cdft</TITLE>
  <TYPE>Scilab Function</TYPE>
  <DATE>Dec 1997</DATE>
  <SHORT_DESCRIPTION name="cdft"> cumulative distribution function Student's T distribution</SHORT_DESCRIPTION>
  <CALLING_SEQUENCE>
    <CALLING_SEQUENCE_ITEM>[P,Q]=cdft(&quot;PQ&quot;,T,Df)  </CALLING_SEQUENCE_ITEM>
    <CALLING_SEQUENCE_ITEM>[T]=cdft(&quot;T&quot;,Df,P,Q)  </CALLING_SEQUENCE_ITEM>
    <CALLING_SEQUENCE_ITEM>[Df]=cdft(&quot;Df&quot;,P,Q,T)  </CALLING_SEQUENCE_ITEM>
  </CALLING_SEQUENCE>
  <PARAM>
    <PARAM_INDENT>
      <PARAM_ITEM>
        <PARAM_NAME>P,Q,T,Df</PARAM_NAME>
        <PARAM_DESCRIPTION>
          <SP>: six real vectors of the same size.</SP>
        </PARAM_DESCRIPTION>
      </PARAM_ITEM>
      <PARAM_ITEM>
        <PARAM_NAME>P,Q (Q=1-P)  </PARAM_NAME>
        <PARAM_DESCRIPTION>
          <SP>: The integral from -infinity to t of the t-density. Input range: (0,1].</SP>
        </PARAM_DESCRIPTION>
      </PARAM_ITEM>
      <PARAM_ITEM>
        <PARAM_NAME>T</PARAM_NAME>
        <PARAM_DESCRIPTION>
          <SP>: Upper limit of integration of the t-density. Input range: ( -infinity, +infinity). Search range: [ -1E150, 1E150 ]</SP>
        </PARAM_DESCRIPTION>
      </PARAM_ITEM>
      <PARAM_ITEM>
        <PARAM_NAME>DF:  </PARAM_NAME>
        <PARAM_DESCRIPTION>
          <SP>Degrees of freedom of the t-distribution. Input range: (0 , +infinity). Search range: [1e-300, 1E10]</SP>
        </PARAM_DESCRIPTION>
      </PARAM_ITEM>
    </PARAM_INDENT>
  </PARAM>
  <DESCRIPTION>
    <P>
    Calculates any one parameter of the T distribution given
    values for the others.</P>
    <P>
    Formula  26.5.27  of   Abramowitz   and  Stegun,   Handbook   of
    Mathematical Functions  (1966) is used to reduce the computation
    of the cumulative distribution function to that of an incomplete
    beta.</P>
    <P>
    Computation of other parameters involve a seach for a value that
    produces  the desired  value  of P.   The search relies  on  the
    monotinicity of P with the other parameter.</P>
  </DESCRIPTION>
</MAN>
