$chart = new Highchart();

$chart->chart->renderTo = "container";
$chart->chart->type = "column";
$chart->title->text = "Column chart with negative values";
$chart->xAxis->categories = array(
    'Apples',
    'Oranges',
    'Pears',
    'Grapes',
    'Bananas'
);

$chart->tooltip->formatter = new HighchartJsExpr("function() {
    return '' + this.series.name +': '+ this.y +'';}");

$chart->credits->enabled = false;

$chart->series[] = array(
    'name' => "John",
    'data' => array(
        5,
        3,
        4,
        7,
        2
    )
);

$chart->series[] = array(
    'name' => "Jane",
    'data' => array(
        2,
        - 2,
        - 3,
        2,
        1
    )
);

$chart->series[] = array(
    'name' => "Joe",
    'data' => array(
        3,
        4,
        4,
        - 2,
        5
    )
);