Question

I am trying to make a flot chart using values from MySQL database. SO i did

//creating array of pairs of x and y values

$dataArray = array();
while ($row = mysql_fetch_assoc()) { //or whatever
    $dataArray[] = array( $row['xvalue'], $row['yvalue'] );
}
?>

<script type="text/javascript">
    //puting array in javascript
    var dataArray = <?php echo json_encode($dataArray); ?>;

    //ploting the graph
    $(function () {
         $.plot($("#placeholder"), [ dataArray ]);
    });
</script>

Everything works fine
But now the problem is in modifying the values(contents) of “$dataArray” .
I want to modify all the yvalues while xvalue remains same.

Answer 1

you could use array_walk_recursive. IN this example i create an array with x/y values and calculate add 1000 to the y value:

<?php
$a[]=array(10,20);
$a[]=array(10,30);

function calc(&$v,$k){
if($k==1){
    $v = $v+1000;  //Calculate
    }
}

$b=array_walk_recursive($a, "calc");
print_r($a);

?>

returns:

Array
(
    [0] => Array
        (
            [0] => 10
            [1] => 1020
        )

    [1] => Array
        (
            [0] => 10
            [1] => 1030
        )

)