JPGraph adding series values together...

Question

I'm sure I'm doing something stupid here but can someone explain why jpgraph is adding two series values together? I'm specifically talking about the values $a1[3] and $a2[3] as well as $a1[10] and $a2[10] being added together. You can see the graphs here and the code is pasted below:

<?php
require_once ('src/jpgraph.php');
require_once ('src/jpgraph_date.php');
require_once ('src/jpgraph_line.php');

$x = array(
'8/4/2010',
'8/5/2010',
'8/6/2010',
'8/10/2010',
'8/11/2010',
'8/12/2010',
'8/13/2010',
'8/14/2010',
'8/15/2010',
'8/16/2010',
'8/17/2010');


$a1 = array(
'474',
'18113',
'14420',
'16651',
'11129',
'12112',
'14441',
'0',
'0',
'10206',
'11702');

$a2 = array(
'0',
'0',
'0',
'8003',
'0',
'504',
'0',
'9204',
'783',
'0',
'7892'
);

// Create the graph. 
$graph  = new Graph(600, 400);
$graph->title->Set('A2');
$graph->SetScale('intlin');
$graph->SetMargin(60,30,60,120);
$graph->xaxis->SetTickSide(SIDE_BOTTOM);
$graph->yaxis->SetTickSide(SIDE_LEFT);

$p0 =new LinePlot($a1);
$p0->value->Show();
$p0->SetLegend('A1');
$p0->setWeight( 3 );
$p0->SetColor('red');

$p1 =new LinePlot($a2);
$p1->value->Show();
$p1->SetLegend('A2');
$p1->setWeight( 3 );
$p1->SetColor('blue');


$ap = new AccLinePlot(array($p1, $p0));

$graph->xaxis->SetTickLabels($x);
$graph->xaxis->SetTextLabelInterval(4);
$graph->Add($ap);
$graph->xaxis->SetLabelAngle(90); 
$graph->Stroke();

Answer 1

I think you are missing the graph->Add. Try the following:

$p0 = new LinePlot($a1);
$p0->value->Show();
$p0->SetLegend('A1');
$p0->setWeight( 3 );
$p0->SetColor('red');
$graph->Add($p0);

$p1 = new LinePlot($a2);
$p1->value->Show();
$p1->SetLegend('A2');
$p1->setWeight( 3 );
$p1->SetColor('blue');
$graph->AddY(0,$p1);
$graph->ynaxis[0]->SetColor('blue');

$graph->Stroke();