| <html lang="en"> |
| <head> |
| <title>PACK - 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="OR.html#OR" title="OR"> |
| <link rel="next" href="PARITY.html#PARITY" title="PARITY"> |
| <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, 2012 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="PACK"></a> |
| <p> |
| Next: <a rel="next" accesskey="n" href="PARITY.html#PARITY">PARITY</a>, |
| Previous: <a rel="previous" accesskey="p" href="OR.html#OR">OR</a>, |
| Up: <a rel="up" accesskey="u" href="Intrinsic-Procedures.html#Intrinsic-Procedures">Intrinsic Procedures</a> |
| <hr> |
| </div> |
| |
| <h3 class="section">8.188 <code>PACK</code> — Pack an array into an array of rank one</h3> |
| |
| <p><a name="index-PACK-921"></a><a name="index-array_002c-packing-922"></a><a name="index-array_002c-reduce-dimension-923"></a><a name="index-array_002c-gather-elements-924"></a> |
| <dl> |
| <dt><em>Description</em>:<dd>Stores the elements of <var>ARRAY</var> in an array of rank one. |
| |
| <p>The beginning of the resulting array is made up of elements whose <var>MASK</var> |
| equals <code>TRUE</code>. Afterwards, positions are filled with elements taken from |
| <var>VECTOR</var>. |
| |
| <br><dt><em>Standard</em>:<dd>Fortran 95 and later |
| |
| <br><dt><em>Class</em>:<dd>Transformational function |
| |
| <br><dt><em>Syntax</em>:<dd><code>RESULT = PACK(ARRAY, MASK[,VECTOR]</code> |
| |
| <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 any type. |
| <br></td></tr><tr align="left"><td valign="top" width="15%"><var>MASK</var> </td><td valign="top" width="70%">Shall be an array of type <code>LOGICAL</code> and |
| of the same size as <var>ARRAY</var>. Alternatively, it may be a <code>LOGICAL</code> |
| scalar. |
| <br></td></tr><tr align="left"><td valign="top" width="15%"><var>VECTOR</var> </td><td valign="top" width="70%">(Optional) shall be an array of the same type |
| as <var>ARRAY</var> and of rank one. If present, the number of elements in |
| <var>VECTOR</var> shall be equal to or greater than the number of true elements |
| in <var>MASK</var>. If <var>MASK</var> is scalar, the number of elements in |
| <var>VECTOR</var> shall be equal to or greater than the number of elements in |
| <var>ARRAY</var>. |
| <br></td></tr></table> |
| |
| <br><dt><em>Return value</em>:<dd>The result is an array of rank one and the same type as that of <var>ARRAY</var>. |
| If <var>VECTOR</var> is present, the result size is that of <var>VECTOR</var>, the |
| number of <code>TRUE</code> values in <var>MASK</var> otherwise. |
| |
| <br><dt><em>Example</em>:<dd>Gathering nonzero elements from an array: |
| <pre class="smallexample"> PROGRAM test_pack_1 |
| INTEGER :: m(6) |
| m = (/ 1, 0, 0, 0, 5, 0 /) |
| WRITE(*, FMT="(6(I0, ' '))") pack(m, m /= 0) ! "1 5" |
| END PROGRAM |
| </pre> |
| <p>Gathering nonzero elements from an array and appending elements from <var>VECTOR</var>: |
| <pre class="smallexample"> PROGRAM test_pack_2 |
| INTEGER :: m(4) |
| m = (/ 1, 0, 0, 2 /) |
| WRITE(*, FMT="(4(I0, ' '))") pack(m, m /= 0, (/ 0, 0, 3, 4 /)) ! "1 2 3 4" |
| END PROGRAM |
| </pre> |
| <br><dt><em>See also</em>:<dd><a href="UNPACK.html#UNPACK">UNPACK</a> |
| </dl> |
| |
| </body></html> |
| |