Array ( 
[0] => stdClass Object ( [id] => 2 [params] => [weight] => 23 [weight_user] => 43 [entry_date] => 2012-03-19 ) 
[1] => stdClass Object ( [id] => 1 [params] => [weight] => 67 [weight_user] => 43 [entry_date] => 2012-03-20 ) 
[2] => stdClass Object ( [id] => 3 [params] => [weight] => 88 [weight_user] => 43 [entry_date] => 2012-03-21 ) 
)

[['2', 23],
 ['1', 67],
 ['3', 88]]

foreach (($this->items) as $ob) {

  $myarray = (($ob->id).",".($ob->weight));
  echo json_encode($myarray);
}

$thisGraph = 				  "
<script type=\"text/javascript\">
google.load('visualization', '1', {packages: ['corechart']});
function drawVisualization() {
var data = google.visualization.arrayToDataTable([
['Jour', 'Tonne par heure','Cible (250 T/H)'],
";			  

foreach ($resultats as $resultat) {
	bla bla bla
	$thisGraph .= $preparedArray[$numeroDeLigne] . ",";
}

$thisGraph .= 
"
]);
var options = {
title : 'Tonnes par heure hors arrêt',
vAxis: {title: \"Quantité\"},
hAxis: {title: \"Jour\"},
seriesType: \"bars\",
isStacked: \"true\",
colors: ['#99cc00', '#003366'],
series: {1: {type: \"line\"}}
};
var chart = new google.visualization.ComboChart(document.getElementById('tonneHeure_div'));
chart.draw(data, options);
}
google.setOnLoadCallback(drawVisualization);
</script>
<div id=\"tonneHeure_div\" style=\"text-align:center; width:900px; height:400px;\"></div>   
";
}

    </script>
    <script type="text/javascript" src="https://www.google.com/jsapi"></script>
    <script type="text/javascript">
      google.load("visualization", "1", {packages:["corechart"]});
      google.setOnLoadCallback(drawChart);
      function drawChart() {
        var data = new google.visualization.DataTable();
        data.addColumn('string', 'Date');
        data.addColumn('number', 'Weight');
        data.addRows(<?php echo "[";  
          foreach (($this->items) as $ob) 
          {
            $valueout = ("[".("'".$ob->entry_date."'").",".($ob->weight)."]".",");
            print ($valueout);
          } echo "]"; 
                  ?>);

        var options = 
        {
          title: 'Weight'
        };

        var chart = new google.visualization.LineChart(document.getElementById('chart_div'));
        chart.draw(data, options);
      }
    </script>

$maDB = $this->getDbo();
$requete = $maDB->getQuery(true);
$requete->select('rd.reportdate pDate' and all the others);
$requete->from('#__blabla AS rd');
$requete->where('rd.reportdate BETWEEN CAST("'.$date1.'" AS DATE) AND CAST("'.$date2.'" AS DATE) AND rd.id = inc.reportdate ORDER BY inc.reportdate');
$maDB->setQuery($requete);
$resultats = $maDB->loadObjectList();

foreach ($resultats as $resultat) {
$AAA.= "['". $value1. "', " . $value2.", 250]".  " - ";
$preparedArray = explode(" - ", $AAA);
}
for ($lineNumber = 0 ; $lineNumber <= $lastLine ; $lineNumber ++) {
$thisGraph .= $preparedArray[$lineNumber ] . ",";
}