File r37/lisp/csl/html/r37_0493.html artifact ea0025cdfb part of check-in 3c4d7b69af



<A NAME=PSI>

<TITLE>PSI</TITLE></A>
<b><a href=r37_idx.html>INDEX</a></b><p><p>



<B>PSI</B> _ _ _  _ _ _  _ _ _  _ _ _ <B>operator</B><P>
<P>
 
 <P>
<P>
The <em>Psi</em> operator returns the Psi (or DiGamma) function. 
<P>
<P>
Psi(x) := df(Gamma(z),z)/ Gamma (z) 
<P>
<P>
 <P> <H3> 
syntax: </H3>
<em>Gamma</em>(&lt;expression&gt;) 
<P>
<P>
<P>
<P>
 <P> <H3> 
examples: </H3>
<P><PRE><TT>
Psi(3); 

  (2*log(2) + psi(1/2) + psi(1) + 3)/2 


on rounded; 

- Psi(1); 

  0.577215664902

</TT></PRE><P>Euler's constant can be found as - Psi(1). 
<P>
<P>
<P>


REDUCE Historical
REDUCE Sourceforge Project | Historical SVN Repository | GitHub Mirror | SourceHut Mirror | NotABug Mirror | Chisel Mirror | Chisel RSS ]