Its easy to create a line-bar combination chart in chartphp with multiple axis support.

Step 1: Include Charts 4 PHP Library

include("../../lib/inc/chartphp_dist.php");
$p = new chartphp();

Step 2: Configure Data array

$linebar_bar_data =
array(
array(
array("Jan",80.25),
array("Feb",138.75),
array("Mar",185.50),
array("Apr",370.50),
array("May",266.80),
array("Jun",350),
array("Jul",245),
array("Aug",129),
array("Sep",490),
array("Oct",323),
array("Nov",255),
array("Dec",450))
);

$linebar_line_data =
array(
array(
array("Jan",145),
array("Feb",129),
array("Mar",190),
array("Apr",323),
array("May",285),
array("Jun",250),
array("Jul",245),
array("Aug",129),
array("Sep",450),
array("Oct",412),
array("Nov",185),
array("Dec",490))
);

$p->data = array($linebar_bar_data, $linebar_line_data) ;

Step 3: Set Chart type

$p->chart_type = "line-bar";

Step 4: Render Chart

$out = $p->render("c1");

For complete code, please visit our demo center.