
<A NAME=ROUNDBF>

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



<B>ROUNDBF</B> _ _ _  _ _ _  _ _ _  _ _ _ <B>switch</B><P>
<P>
 
When 
<A HREF=r37_0330.html>rounded</A> is on, the normal defaults cause underflows to
 be 
converted to zero. If you really want the small number that results in 
such cases, <em>roundbf</em> can be turned on. 
<P>
<P>
 <P> <H3> 
examples: </H3>
<P><PRE><TT>
on rounded; 

exp(-100000.1^2); 

  0 


on roundbf; 

exp(-100000.1^2); 

  1.18441281937E-4342953505

</TT></PRE><P>If a polynomial is input in 
<A HREF=r37_0330.html>rounded</A> mode at the default 
precision into any 
<A HREF=r37_0438.html>roots</A> function, and it is not possible to 
represent any of the coefficients of the polynomial precisely in the 
system floating point representation, the switch <em>roundbf</em> will be 
automatically turned on. All rounded computation will use the internal 
bigfloat representation until the user subsequently turns <em>roundbf</em> 
off. (A message is output to indicate that this condition is in effect.) 
<P>
<P>
<P>
