สอบถามการสร้างกราฟเส้นจาก jpgraph ครับ เรื่องการกำหนดแกน X ครับ

<?php
include ("C:\AppServ\www\project\jpgraph-3.5.0b1\src\jpgraph.php");
include ("C:\AppServ\www\project\jpgraph-3.5.0b1\src\jpgraph_line.php");
//$g = new Graph(800, 300,"auto",60);
$g = new Graph(1200, 450);
$g ->title ->Set("Today Temp");


$g -> SetScale("textint");
$labels = array("01:00","02:00","03:00","04:00","05:00","06:00","07:00","08:00","09:00", "10:00","11:00","12:00","13:00","14:00","15:00","16:00","17:00","18:00","19:00","20:00","21:00","22:00","23:00","24:00");
$g -> xaxis -> SetTickLabels($labels);
$g->xaxis->SetLabelAngle (45);
 
// ติดต่อ ฐานข้อมูล เลือกข้อมูลขึ้นมาเพื่อแสดงกราฟ 
$objConnect = mysql_connect("localhost","root","123456") or die("Error Connect to Database"); 
$objDB = mysql_select_db("test"); 

$strSQL = "SELECT * FROM uploadfile3;"; 
$objQuery = mysql_query($strSQL) or die ("Error Query [".$strSQL."]"); 

 
// เตรียมข้อมุลที่จะแสดง เพื่อสร้างกราฟ 
$datay=array(); 
while($objResult = mysql_fetch_array($objQuery)) 
{ 
$datay[] = $objResult["ph"];  
} 

//$data = array();
$line = new LinePlot($datay);
$line->value->Show();
$g->Add($line);
$g->Stroke();


?>