Question

Please I have been trying this but seems difficult. I am trying to make the number of y-axis depend on the user selection. There are 3 sections for user to select from, namely:

1. Time range for the plot
2. ID to plot, which will be taken from database
3. Field to search in the database

If the user selects 2 ID and 2 Field, then I should have 4 different lines on the plot. Which means that:

number of lines = number of ID selected * number of Field selected

With that I know I will get same number for the labels in the legend and also for the number of y-axis to be displayed.

For the example I gave, it should be something like:

• Field_1-ID_1
• Field_2-ID_1
• Field_1-ID_2
• Field_2-ID_2

for the legend label and the y-axis to be produced, but it all depends on the user selection.

Thank you for your attention.

Answer 1

I finally found a way to resolve this by generating from the php side, the elements for the series property in the jqplot in its expected format i.e.

series:[{label:Field_1-ID_1,yaxis:'yaxis'},{label:Field_1-ID_2,yaxis:'y2axis'},{label:Field_2-ID_1,yaxis:'y3axis'},{label:Field_2-ID_2,yaxis:'y4axis'}]

If anyone is interested in how it is done, please check the code below:

$con = mysql_connect($hostname, $username, $password);
if (!$con)
{
 die('Could not connect: ' . mysql_error());
}

mysql_select_db($database, $con);

$unit = mysql_real_escape_string($_GET["units"]);//ID selected by user, e.g.(ID_1,ID_2)
$stat = mysql_real_escape_string($_GET["start"]);//start time
$stop = mysql_real_escape_string($_GET["stop"]);//stop time
$field1 = mysql_real_escape_string($_GET["fieldlist"]);//Field selected by user, e.g.(Field_1,Field_2)

$first=true;
echo "Label=";
echo "[";

$field = explode(",", $field1);
$count=count($field);
$i=0;$j=1;
while($i<$count)
{ 
  $sq="SELECT su_id FROM Station_stat
  WHERE su_id in ($unit) GROUP BY su_id";

  $res = mysql_query($sq);

  while($row = mysql_fetch_array($res)){
  if ($first != true )
    {
        echo ",";
        echo "{label:\"$field[$i] ".$row['su_id']."\",yaxis:\"y".++$j."axis\"}";
    }
  else
      echo "{label:\"$field[$i] ".$row['su_id']."\",yaxis:\"yaxis\"}";
      $first = false;
 }
++$i;
}
echo "];";

The output of that php is like:

Label=[{label:Field_1-ID_1,yaxis:'yaxis'},{label:Field_1-ID_2,yaxis:'y2axis'},{label:Field_2-ID_1,yaxis:'y3axis'},{label:Field_2-ID_2,yaxis:'y4axis'}];

Then in the jqplot function, I set series to be Label:

series:Label