Division by zero in pDraw php class - php

Question

I'm trying to create a PHP script, which could draw a LineChart from MYSQL table.
Everything related with MYSQL works fine, but when I want to draw a LineChart using pChart, I'm getting error (Warning: Division by zero in ...\class\pDraw.class.php on line 3113). Please help me!
Here's the code:
<?php
include("class/pData.class.php");
include("class/pDraw.class.php");
include("class/pImage.class.php");
$filename = 'file.txt';
echo 'Status info:<br />';
$myData = new pData();
$db=mysql_connect("localhost","root","") or die("Failed to connect with database!");
echo '<br>* Connected to database successfully - OK<br />';
mysql_select_db("database", $db);
mysql_query("CREATE TABLE `measures` (
timestamp INT(10),
temperature INT(10),
humidity INT(10),
PRIMARY KEY (timestamp));");
echo "<br> * Table created successfully or it has been created earlier - OK<br />";
mysql_query("LOAD DATA INFILE '$filename' IGNORE INTO TABLE measures
FIELDS TERMINATED BY ','
LINES TERMINATED BY '\n' ")
or die("MySQL - Query Error - " . MySQL_Error());
echo "<br>* Data imported successfully - OK<br />";
$Requete = "SELECT * FROM `measures`";
$Result = mysql_query($Requete,$db);
while($row = mysql_fetch_array($Result))
{
$timestamp[] = $row["timestamp"];
$temperature[] = $row["temperature"];
$humidity[] = $row["humidity"];
}
$myData->addPoints($timestamp,"Timestamp");
$myData->addPoints($temperature,"Temperature");
$myData->addPoints($humidity,"Humidity");
$myData->setAbscissa("Timestamp");
$myData->setSerieOnAxis("Humidity", 1);
$myData->setXAxisName("Time");
$myData->setXAxisDisplay(AXIS_FORMAT_TIME,"H:i");
$myData->setAxisName(0,"Temperature");
$myData->setAxisUnit(0,"°C");
$myData->setAxisName(1,"Humidity");
$myData->setAxisUnit(0,"%");
$myPicture = new pImage(700,230,$myData);
$myPicture->drawLineChart();
?>
EDIT:
Here's the function containing line 3113 in pDraw.php
function scaleComputeY($Values,$Option="",$ReturnOnly0Height=FALSE)
{
$AxisID = isset($Option["AxisID"]) ? $Option["AxisID"] : 0;
$SerieName = isset($Option["SerieName"]) ? $Option["SerieName"] : NULL;
$Data = $this->DataSet->getData();
if ( !isset($Data["Axis"][$AxisID]) ) { return(-1); }
if ( $SerieName != NULL ) { $AxisID = $Data["Series"][$SerieName]["Axis"]; }
if ( !is_array($Values) ) { $tmp = $Values; $Values = ""; $Values[0] = $tmp; }
$Result = "";
if ( $Data["Orientation"] == SCALE_POS_LEFTRIGHT )
{
$Height = ($this->GraphAreaY2 - $this->GraphAreaY1) - $Data["Axis"][$AxisID]["Margin"]*2;
$ScaleHeight = $Data["Axis"][$AxisID]["ScaleMax"] - $Data["Axis"][$AxisID]["ScaleMin"];
$Step = $Height / $ScaleHeight;
if ( $ReturnOnly0Height )
{ foreach($Values as $Key => $Value) { if ( $Value == VOID ) { $Result[] = VOID; } else { $Result[] = $Step * $Value; } } }
else
{ foreach($Values as $Key => $Value) { if ( $Value == VOID ) { $Result[] = VOID; } else { $Result[] = $this->GraphAreaY2 - $Data["Axis"][$AxisID]["Margin"] - ($Step * ($Value-$Data["Axis"][$AxisID]["ScaleMin"])); } } }
}
else
{
$Width = ($this->GraphAreaX2 - $this->GraphAreaX1) - $Data["Axis"][$AxisID]["Margin"]*2;
$ScaleWidth = $Data["Axis"][$AxisID]["ScaleMax"] - $Data["Axis"][$AxisID]["ScaleMin"];
$Step = $Width / $ScaleWidth;
if ( $ReturnOnly0Height )
{ foreach($Values as $Key => $Value) { if ( $Value == VOID ) { $Result[] = VOID; } else { $Result[] = $Step * $Value; } } }
else
{ foreach($Values as $Key => $Value) { if ( $Value == VOID ) { $Result[] = VOID; } else { $Result[] = $this->GraphAreaX1 + $Data["Axis"][$AxisID]["Margin"] + ($Step * ($Value-$Data["Axis"][$AxisID]["ScaleMin"])); } } }
}
if ( count($Result) == 1 )
return($Result[0]);
else
return($Result);
}

Answer 1

You can fix it by changing this line:
$Step = $Width / $ScaleWidth;
to:
if ($ScaleWidth > 0) {
$Step = $Width / $ScaleWidth;
} else {
$Step = 1; // or change this to 0 if it doesn't work, I am not sure what this line does.
}