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<HTML>
<HEAD>
<TITLE>INTERSECTION</TITLE>
</HEAD>
<BODY bgcolor="#FFFFFF" fgcolor="#000000">
<P><A NAME="intersection"></A>
<font size="+3" color="green"><B>INTERSECTION</B></font></P>
<P>
<TABLE border="1" cols="2" frame="box" rules="all" width="572">
<TR>
<TD width="15%" valign="top"><B>Syntax</B>:</TD>
<TD width="85%"><CODE>
vout = v1 /& v2</CODE>
</TD></TR>
</table></p>
<p>
The intersection operator, <code>/&</code>, is a binary operator that only accepts vectors
as operands, and returns a vector which contains the intersection of the elements of
these two vectors.</p>
<p>
All vectors have an order property. Vectors are either in ascending order, descending
order, or un-ordered. The type is displayed in the
<CODE><a href="../../ShowCommand/showcommand.htm">SHOW</a></CODE>
command. For now, being ordered only has an affect on the vector union,
<CODE>/|</CODE>, and the vector intersection, <CODE>/&</CODE>. These operations are
much faster if the vector operands are ordered. The
<CODE><a href="../../Functions/VariableCharacteristics/Where/where.htm">WHERE</a></CODE>
function produces an ascending order vector, as does the
<CODE><a href="../../SortCommand/sortcommand.htm">SORT/UP</a></CODE>
command. The <CODE><a href="../../SortCommand/sortcommand.htm">SORT/DOWN</a></CODE> command produces a
descending order vector. This vector property will be utilized more in the future to
enhance speed and efficiency.</P>
<p>
<font size="+1" color="green">Example</font></p>
<p>
To illustrate vector intersection, suppose you have two vectors:</p>
<p>
<CODE>X = [1;2;3;4;5;6;7]</CODE> and <CODE>Y = [-2;-1;0;1;2]</CODE></p>
<p>
Then: <CODE>X/&Y = [1;2]</CODE></p>
<P>
<a href="../union/union.htm"><img border="0" src="../../shadow_left.gif">
<font size="+1" color="olive">vector union</font></a><br />
<a href="../append/append.htm"><img border="0" src="../../shadow_right.gif">
<font size="+1" color="olive">append vectors or strings</font></a>
</P>
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