<html lang="en"> <head> <title>PRODUCT - The GNU Fortran Compiler</title> <meta http-equiv="Content-Type" content="text/html"> <meta name="description" content="The GNU Fortran Compiler"> <meta name="generator" content="makeinfo 4.13"> <link title="Top" rel="start" href="index.html#Top"> <link rel="up" href="Intrinsic-Procedures.html#Intrinsic-Procedures" title="Intrinsic Procedures"> <link rel="prev" href="PRESENT.html#PRESENT" title="PRESENT"> <link rel="next" href="RADIX.html#RADIX" title="RADIX"> <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> <!-- Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with the Invariant Sections being ``Funding Free Software'', the Front-Cover Texts being (a) (see below), and with the Back-Cover Texts being (b) (see below). A copy of the license is included in the section entitled ``GNU Free Documentation License''. (a) The FSF's Front-Cover Text is: A GNU Manual (b) The FSF's Back-Cover Text is: You have freedom to copy and modify this GNU Manual, like GNU software. Copies published by the Free Software Foundation raise funds for GNU development.--> <meta http-equiv="Content-Style-Type" content="text/css"> <style type="text/css"><!-- pre.display { font-family:inherit } pre.format { font-family:inherit } pre.smalldisplay { font-family:inherit; font-size:smaller } pre.smallformat { font-family:inherit; font-size:smaller } pre.smallexample { font-size:smaller } pre.smalllisp { font-size:smaller } span.sc { font-variant:small-caps } span.roman { font-family:serif; font-weight:normal; } span.sansserif { font-family:sans-serif; font-weight:normal; } --></style> </head> <body> <div class="node"> <a name="PRODUCT"></a> <p> Next: <a rel="next" accesskey="n" href="RADIX.html#RADIX">RADIX</a>, Previous: <a rel="previous" accesskey="p" href="PRESENT.html#PRESENT">PRESENT</a>, Up: <a rel="up" accesskey="u" href="Intrinsic-Procedures.html#Intrinsic-Procedures">Intrinsic Procedures</a> <hr> </div> <h3 class="section">8.193 <code>PRODUCT</code> — Product of array elements</h3> <p><a name="index-PRODUCT-921"></a><a name="index-array_002c-product-922"></a><a name="index-array_002c-multiply-elements-923"></a><a name="index-array_002c-conditionally-multiply-elements-924"></a><a name="index-multiply-array-elements-925"></a> <dl> <dt><em>Description</em>:<dd>Multiplies the elements of <var>ARRAY</var> along dimension <var>DIM</var> if the corresponding element in <var>MASK</var> is <code>TRUE</code>. <br><dt><em>Standard</em>:<dd>Fortran 95 and later <br><dt><em>Class</em>:<dd>Transformational function <br><dt><em>Syntax</em>:<dd> <p><table summary=""><tr align="left"><td valign="top" width="80%"><code>RESULT = PRODUCT(ARRAY[, MASK])</code> <br></td></tr><tr align="left"><td valign="top" width="80%"><code>RESULT = PRODUCT(ARRAY, DIM[, MASK])</code> <br></td></tr></table> <br><dt><em>Arguments</em>:<dd> <p><table summary=""><tr align="left"><td valign="top" width="15%"><var>ARRAY</var> </td><td valign="top" width="70%">Shall be an array of type <code>INTEGER</code>, <code>REAL</code> or <code>COMPLEX</code>. <br></td></tr><tr align="left"><td valign="top" width="15%"><var>DIM</var> </td><td valign="top" width="70%">(Optional) shall be a scalar of type <code>INTEGER</code> with a value in the range from 1 to n, where n equals the rank of <var>ARRAY</var>. <br></td></tr><tr align="left"><td valign="top" width="15%"><var>MASK</var> </td><td valign="top" width="70%">(Optional) shall be of type <code>LOGICAL</code> and either be a scalar or an array of the same shape as <var>ARRAY</var>. <br></td></tr></table> <br><dt><em>Return value</em>:<dd>The result is of the same type as <var>ARRAY</var>. <p>If <var>DIM</var> is absent, a scalar with the product of all elements in <var>ARRAY</var> is returned. Otherwise, an array of rank n-1, where n equals the rank of <var>ARRAY</var>, and a shape similar to that of <var>ARRAY</var> with dimension <var>DIM</var> dropped is returned. <br><dt><em>Example</em>:<dd> <pre class="smallexample"> PROGRAM test_product INTEGER :: x(5) = (/ 1, 2, 3, 4 ,5 /) print *, PRODUCT(x) ! all elements, product = 120 print *, PRODUCT(x, MASK=MOD(x, 2)==1) ! odd elements, product = 15 END PROGRAM </pre> <br><dt><em>See also</em>:<dd><a href="SUM.html#SUM">SUM</a> </dl> </body></html>