Optimizing setCellValueExplicit() in PHPExcel - php

Question

I am dealing with 700 rows of data in my excel.
And I add on a column this entry:
foreach($data as $k => $v){
$users ->getCell('A'.$k)->setValue($v['Username']);
$users->setCellValueExplicit('B'.$k,
'=INDEX(\'Feed\'!H2:H'.$lastRow.',MATCH(A'.$k.',\'Feed\'!G2:G'.$lastRow.',0))',
PHPExcel_Cell_DataType::TYPE_FORMULA);
}
$users stands for a spreadsheet.
I see that writing 700 cells with the above setCellValueExplicit() takes more than 2 minutes to get processed. If I omit that line it takes 4 seconds for the same machine to process it.
2 minutes can be ok, but what if I have 2000 cells. Is there any way that can be speed optimized?
ps: =VLOOKUP is the same slow as the above function.
Update
The whole idea of the script:
read a CSV file (13 columns and at least 100 rows), write it into a spreadsheet, create a new spreadsheet ($users), read two columns, sort them based to one column and write it to the $users spreadsheet.
Read the columns:
$data = array();
for ($i = 1; $i <= $lastRow; $i++) {
$user = $Feed ->getCell('G'.$i)->getValue();
$number = $Feed ->getCell('H'.$i)->getValue();
$row = array('User' => $user, 'Number' => $number);
array_push($data, $row);
}
Sort the data
function cmpb($a,$b){
//get which string is less or 0 if both are the same
if($a['Number']>$b['Number']){
$cmpb = -1;
}elseif($a['Number']<$b['Number']){
$cmpb = 1;
}else{
$cmpb = 0;
}
//if the strings are the same, check name
if($cmpb == 0){
//compare the name
$cmpb = strcasecmp($a['User'], $b['User']);
}
return $cmpb;
}
usort($data, 'cmpb');
Write data
foreach($data as $k => $v){
$users ->getCell('A'.$k)->setValue($v['Username']);
$users ->getCell("B{$k}")->setValueExplicit("=INDEX('Feed'!H2:H{$lastRow},MATCH(A{$k},'Feed'!G2:G{$lastRow},0))",
PHPExcel_Cell_DataType::TYPE_FORMULA);
}
and also unset the data for memory:
unset($data);
So if comment the line with setValueExplicit everything becomes smoother.

Answer 1

Looking at PHPExcel's source code, this is PHPExcel_Worksheet::setCellValueExplicit function:
public function setCellValueExplicitByColumnAndRow($pColumn = 0, $pRow = 1, $pValue = null, $pDataType = PHPExcel_Cell_DataType::TYPE_STRING)
{
return $this->getCell(PHPExcel_Cell::stringFromColumnIndex($pColumn) . $pRow)->setValueExplicit($pValue, $pDataType);
}
For the data type you're using, PHPExcel_Cell_DataType::TYPE_FORMULA, the PHPExcel_Cell::setValueExplicit function just executes:
case PHPExcel_Cell_DataType::TYPE_FORMULA:
$this->_value = (string)$pValue;
break;
I can't find a logical explanation for the old up on the execution of that particular instruction. Try to replace it for the following and let me know if there was any improvement:
$users ->getCell("B{$k}")->setValueExplicit("=INDEX('Feed'!H2:H{$lastRow},MATCH(A{$k},'Feed'!G2:G{$lastRow},0))", PHPExcel_Cell_DataType::TYPE_FORMULA);
As a last resource my advice would be to time track the execution of the instruction to find the bottleneck.