File r37/lisp/csl/html/r37_0181.html artifact f7b63c1815 part of check-in e1a8550313

<A NAME=STRUCTR>

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



<B>STRUCTR</B> _ _ _  _ _ _  _ _ _  _ _ _ <B>operator</B><P>
<P>
 
 <P>
<P>
The <em>structr</em> operator breaks its argument expression into named 
subexpressions. 
<P>
<P>
 <P> <H3> 
syntax: </H3>
<em>structr</em>(&lt;expression&gt; [,&lt;identifier&gt;[,&lt;identifier&gt; ...
]]) 
<P>
<P>
<P>
&lt;expression&gt; may be any valid REDUCE scalar expression. 
&lt;identifier&gt; may be any valid REDUCE <em>identifier</em>. The first 
identifier 
is the stem for subexpression names, the second is the name to be assigned 
to the structured expression. 
<P>
<P>
 <P> <H3> 
examples: </H3>
<P><PRE><TT>
structr(sqrt(x**2 + 2*x) + sin(x**2*z)); 


  ANS1 + ANS2
      where
                       2
          ANS2 := SIN(X *Z)
                             1/2
          ANS1 := ((X + 2)*X)


ans3; 

  ANS3 


on fort; 

structr((x+1)**5 + tan(x*y*z),var,aa); 


  VAR1=TAN(X*Y*Z)
  AA=VAR1+X**5+5.*X**4+10.*X**3+10.X**2+5.*X+1

</TT></PRE><P>The second argument to <em>structr</em> is optional. If it is not 
given, the 
default stem <em>ANS</em> is used by REDUCE to construct names for the 
subexpression. The names are only for display purposes: REDUCE does not 
store the names and their values unless the switch 
<A HREF=r37_0331.html>savestructr</A> is 
on. 
<P>
<P>
If a third argument is given, the structured expression as a whole is named by 
this argument, when 
<A HREF=r37_0289.html>fort</A> is on. The expression is not stored 
under this 
name. You can send these structured Fortran expressions to a file with the 
<em>out</em> command. 
<P>
<P>
<P>