From b88a6f49471f1c4ef92b26a0efb196b873725810 Mon Sep 17 00:00:00 2001
From: MarkBaker <mark@lange.demon.co.uk>
Date: Mon, 4 May 2015 23:41:52 +0100
Subject: [PATCH] Calculation example with cyclic formula

---
 Examples/13calculationCyclicFormulae.php | 97 ++++++++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 Examples/13calculationCyclicFormulae.php

diff --git a/Examples/13calculationCyclicFormulae.php b/Examples/13calculationCyclicFormulae.php
new file mode 100644
index 0000000..8512a3e
--- /dev/null
+++ b/Examples/13calculationCyclicFormulae.php
@@ -0,0 +1,97 @@
+<?php
+/**
+ * PHPExcel
+ *
+ * Copyright (C) 2006 - 2014 PHPExcel
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * @category   PHPExcel
+ * @package    PHPExcel
+ * @copyright  Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)
+ * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt	LGPL
+ * @version    ##VERSION##, ##DATE##
+ */
+
+/** Error reporting */
+error_reporting(E_ALL);
+ini_set('display_errors', TRUE);
+ini_set('display_startup_errors', TRUE);
+date_default_timezone_set('Europe/London');
+
+define('EOL',(PHP_SAPI == 'cli') ? PHP_EOL : '<br />');
+
+date_default_timezone_set('Europe/London');
+
+/** Include PHPExcel */
+require_once dirname(__FILE__) . '/../Classes/PHPExcel.php';
+
+
+// Create new PHPExcel object
+echo date('H:i:s') , " Create new PHPExcel object" , EOL;
+$objPHPExcel = new PHPExcel();
+
+// Add some data, we will use some formulas here
+echo date('H:i:s') , " Add some data and formulas" , EOL;
+$objPHPExcel->getActiveSheet()->setCellValue('A1', '=B1')
+                              ->setCellValue('A2', '=B2+1')
+                              ->setCellValue('B1', '=A1+1')
+                              ->setCellValue('B2', '=A2');
+
+PHPExcel_Calculation::getInstance($objPHPExcel)->cyclicFormulaCount = 100;
+
+// Calculated data
+echo date('H:i:s') , " Calculated data" , EOL;
+for($row = 1; $row <= 2; ++$row) {
+    for ($col = 'A'; $col != 'C'; ++$col) {
+        if ((!is_null($formula = $objPHPExcel->getActiveSheet()->getCell($col.$row)->getValue())) &&
+			($formula[0] == '=')) {
+            echo 'Value of ' , $col , $row , ' [' , $formula , ']: ' ,
+                               $objPHPExcel->getActiveSheet()->getCell($col.$row)->getCalculatedValue() . EOL;
+        }
+    }
+}
+
+
+// Save Excel 2007 file
+echo date('H:i:s') , " Write to Excel2007 format" , EOL;
+$callStartTime = microtime(true);
+
+$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel2007');
+
+//
+//  If we set Pre Calculated Formulas to true then PHPExcel will calculate all formulae in the
+//    workbook before saving. This adds time and memory overhead, and can cause some problems with formulae
+//    using functions or features (such as array formulae) that aren't yet supported by the calculation engine
+//  If the value is false (the default) for the Excel2007 Writer, then MS Excel (or the application used to
+//    open the file) will need to recalculate values itself to guarantee that the correct results are available.
+//
+//$objWriter->setPreCalculateFormulas(true);
+$objWriter->save(str_replace('.php', '.xlsx', __FILE__));
+$callEndTime = microtime(true);
+$callTime = $callEndTime - $callStartTime;
+
+echo date('H:i:s') , " File written to " , str_replace('.php', '.xlsx', pathinfo(__FILE__, PATHINFO_BASENAME)) , EOL;
+echo 'Call time to write Workbook was ' , sprintf('%.4f',$callTime) , " seconds" , EOL;
+// Echo memory usage
+echo date('H:i:s') , ' Current memory usage: ' , (memory_get_usage(true) / 1024 / 1024) , " MB" , EOL;
+
+
+// Echo memory peak usage
+echo date('H:i:s') , " Peak memory usage: " , (memory_get_peak_usage(true) / 1024 / 1024) , " MB" , EOL;
+
+// Echo done
+echo date('H:i:s') , " Done writing file" , EOL;
+echo 'File has been created in ' , getcwd() , EOL;