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| <H2>22.6 Member Functions</H2> |
| <A NAME="idx471"><!></A> |
| <P>The member functions of class <B><I><A HREF="../stdlibref/valarray.html">valarray</A></I></B> include the <SAMP>size()</SAMP> function, which returns the size of a <B><I>valarray</I></B>, and the <SAMP>sum()</SAMP> function, which returns the sum of all elements in a <B><I>valarray</I></B>. The functions <SAMP>min()</SAMP> and <SAMP>max()</SAMP> return, respectively, the minimum and maximum values in a <B><I>valarray</I></B>.</P> |
| <P>Class <B><I><A HREF="../stdlibref/valarray.html">valarray</A></I></B> also contains two shift functions. Both functions shift elements a specified number of steps to the left, where the <SAMP>0</SAMP><SUP>th</SUP> element is defined as the leftmost. The <SAMP>shift()</SAMP> function fills in at the right with <SAMP>0</SAMP>s or <SAMP>T()</SAMP>s. The <SAMP>cshift()</SAMP> function performs a circular shift or <I>rotation</I> so that the <SAMP>i</SAMP><SUP>th</SUP> element becomes the element at location <SAMP>self.length() - n - i</SAMP>, where <SAMP>i</SAMP> runs from <SAMP>0</SAMP> to <SAMP>n</SAMP>, and <SAMP>n</SAMP> is the number of steps to shift. Both functions return a new <B><I>valarray</I></B>, but the original is not changed. For example:</P> |
| |
| <UL><PRE> |
| int a[5] = {1,2,3,4,5}; |
| std::valarray<int> v(a,5); |
| std::valarray<int> v2 = v.shift(2); // v2 = {3,4,5,0,0} |
| v2 = v.cshift(2); // v2 = {3,4,5,1,2} |
| </PRE></UL> |
| <P>Class <B><I><A HREF="../stdlibref/valarray.html">valarray</A></I></B> provides two versions of the <SAMP>apply()</SAMP> function. These functions apply a user-specified function to each element in the array. Again, these return a new array with the result leaving the original array unaltered.</P> |
| <P>Finally, as we noted in the discussion on constructors, <B><I><A HREF="../stdlibref/valarray.html">valarray</A></I></B> has a resize function that allows a program to change the number of elements contained by that array. The original elements, if any, are lost in the process since the function re-initializes all elements in the newly-sized array.</P> |
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