[SOLVED] Using the GD Class to draw a dynamic Line-Graph

[Barand]

How are you passing the months and values to the graph?

[rilana]

$x1=$originx-$x_gap;
$y1=$originy;
$first_one="yes";
while($nt=mysql_fetch_array($qt)){
//echo "$nt[month], $nt[sales]";
$x2=$x1+$x_gap; // Shifting in X axis
$y2=$y_max-$nt[miv_wert]; // Coordinate of Y axis
$datum= date("F", strtotime($nt['miv_datum']));

imagettftext($im,8,90,$x2+5,$y0+295,$graph_color,$font,$datum);
//Line above is to print month names on the graph



if($first_one=="no"){ // this is to prevent from starting $x1= and $y1=0
imagesetthickness ($im,$th);
imageline ($im,$x1, $y1,$x2,$y2,$text_colorMiv); // Drawing the line between two points
imageline ($im,0,560,300,560,$grid_color);
}
$x1=$x2; // Storing the value for next draw
$y1=$y2;
$first_one="no"; // Now flag is set to allow the drawing
}

[Barand]

try

$x1=$originx-$x_gap;
$y1=$originy;
$first_one="yes";

$prevDatum = '';
while($nt=mysql_fetch_array($qt)){
    //echo "$nt[month], $nt[sales]";
    $x2=$x1+$x_gap; // Shifting in X axis
    $y2=$y_max-$nt[miv_wert]; // Coordinate of Y axis
    $datum = date("F", strtotime($nt['miv_datum']));
    
    $month = $datum==$prevDatum ? '' : $datum;                           // check for same month name
    $prevDatum = $datum;
    
    imagettftext($im,8,90,$x2+5,$y0+295,$graph_color,$font,$month);
    //Line above is to print month names on the graph



    if($first_one=="no"){ // this is to prevent from starting $x1= and $y1=0
    imagesetthickness ($im,$th);
    imageline ($im,$x1, $y1,$x2,$y2,$text_colorMiv); // Drawing the line between two points
    imageline ($im,0,560,300,560,$grid_color);
    }
    $x1=$x2; // Storing the value for next draw
    $y1=$y2;
    $first_one="no"; // Now flag is set to allow the drawing
}

[rilana]

yes that works perfect. I dont understand what $month = $datum==$prevDatum ? '' : $datum; this means.

month is datum does it equal prevDatum '' divided by datum??? Where do I learn syntax like this so it makes sens to me?

[Barand]

it's called "ternary" if you want to look it up.

 

 

$var = <condition> ? <value if condition true> : <value if condition false>;

 

Short for

 

if ($datum == $prevDatum)          // is datum same as previous datum
{
    $month = '';                          // if it is, print '' instead of repeating the month
}
else
{
    $month = $datum;                 // it's different so print new value
}

[rilana]

ternary was interesting... I have to keep it in mind! I read the tutorial in the front about handling database. It's a tutorial on how to set up a script that allows you to add, edit and delet all in the same script. I am still working on the backend of this thing, and it was easy to set up a form that enters values to the database. But now I am stuck. The tutorial helped me understand a lot, but now that I am trying to change it to my needs, I am having problems. In the end of the script there is a form

echo <<<NEWENTRY
   <tr>
      <td bgcolor = 'gray'></td>
      <td><input type = 'text' miv_datum = 'miv_datum'></td>
        <td><input type = 'text' miv_wert = 'miv_wert'></td>

      <td bgcolor = 'gray'></td>
   </tr><tr>
      <td></td>
      <td align = 'center'><input type = 'submit' value = 'submit'></td>
      <td></td>
   </tr>
</table>
</form>	 

Somehow this submit button is suposed to send the input text value to the post function.

// INSERT: if we have a name to add...
if($_POST['miv_datum']['miv_wert']) {
   // little bit of cleaning...
   $miv_datum = mysql_real_escape_string($_POST['miv_datum']);
   $miv_wert = mysql_real_escape_string($_POST['miv_wert']);


   // insert new name into table
   $sql = "INSERT INTO miv (ID, miv_datum, miv_wert) VALUES ('','$miv_datum','miv_wert')";
   $result = mysql_query($sql, $conn) or trigger_error("SQL", E_USER_ERROR);
}

Now the tutorial was only with one text-field in the form, so maby I am doing something wrong by adding more values. Am I supused to make a string or something like that? I tryed different things out, but it's not working. Thank's for helping. Rilana

[Barand]

what's your form tag?

[rilana]

I am not shoure do you meen this?

 

echo <<<LISTCOLS
<form action = '{$_SERVER['PHP_SELF']}' method = 'post'>
<table border = '1'>
   <tr>
      <td><a href = '{$_SERVER['PHP_SELF']}?orderby=ID'>id</td>
      <td><a href = '{$_SERVER['PHP_SELF']}?orderby=miv_datum'>miv_datum</td>
  <td><a href = '{$_SERVER['PHP_SELF']}?orderby=miv_wert'>miv_wert</td>

      <td>delete</td>
   </tr>
LISTCOLS;

[Barand]

inputs need to be

 

<td><input type = 'text' name = 'miv_datum'></td>
        <td><input type = 'text' name = 'miv_wert'></td>

 

 

and to see if data sent

if($_POST['miv_datum'])

 

[rilana]

Hi, sorry for taking so long. Thank you verry much I am almost done now. I just have one last thing to worry about. After one year the graph will be to wide to continue. I could be deleting entrys from the database, but it would be much cooler if I could say something like: if id == 52 show no more then 52 entrys, for example if there are 53 entrys, show id 2 till 53... But I dont realy know how to set this up. I probably have to change the whole coding arround.... Can you give me a hint? here is the part that need to be changed

 

$x1=$originx-$x_gap;
$y1=$originy;
$first_one="yes";
while($nt=mysql_fetch_array($qt)){
//echo "$nt[month], $nt[sales]";
$x2=$x1+$x_gap; // Shifting in X axis
$y2=$y_max-$nt[miv_wert]; // Coordinate of Y axis
$datum= date("d.m.y", strtotime($nt['miv_datum']));




    
imagettftext($im,8,90,$x2+5,$y0+295,$graph_color,$font,$datum);
//Line above is to print month names on the graph


if($first_one=="no"){ // this is to prevent from starting $x1= and $y1=0
imagesetthickness ($im,$th);
imageline ($im,$x1, $y1,$x2,$y2,$text_colorMiv); // Drawing the line between two points
imageline ($im,0,560,300,560,$grid_color);
}
$x1=$x2; // Storing the value for next draw
$y1=$y2;
$first_one="no"; // Now flag is set to allow the drawing
}

 

thank you

[Barand]

Change it back at the query where you sect the data and use LIMIT x,y in your SQL, where x is the record to start at and y is the number of records to retrieve.

 

Get a count of the records, then "... ORDER BY date LIMIT (count-52), 52" so you always get the last 52 records on the file.

[rilana]

Hi, thank you so much for your feedback. I tryed several things, but I am doing something wrong.

this works...

 

$qt=mysql_query("select * from miv LIMIT 0, 10");

 

But as soon as I try to do this:

$qt=mysql_query("select * from miv ORDER BY miv_datum LIMIT (count-52), 52");

 

the output is empty, what am I doing wrong? thank you, Rilana

[Barand]

you need to get the count first.

 

$res = mysql_query ("SELECT COUNT(*) FROM miv");
$count = mysql_result($res, 0);
if ($count < 52) $count = 52;
$qt=mysql_query("select * from miv ORDER BY miv_datum LIMIT ($count-52), 52");

[rilana]

ok sorry, I dont get it. It's not working.

 

$res = mysql_query ("SELECT COUNT(*) FROM miv");
$count = mysql_result($res, 0);
if ($count < 52) $count = 52;
$qt=mysql_query("select * from miv ORDER BY miv_datum LIMIT ($count-52), 52");
header ("Content-type: image/jpg");

 

Maby the mysql_fetch_array($qt) does not work this way anymore, could that be a possibility?

 

$x1=$originx-$x_gap;
$y1=$originy;
$first_one="yes";
while($nt=mysql_fetch_array($qt)){
//echo "$nt[month], $nt[sales]";
$x2=$x1+$x_gap; // Shifting in X axis
$y2=$y_max-$nt[miv_wert]; // Coordinate of Y axis
$datum= date("d.m.y", strtotime($nt['miv_datum']));

[rilana]

I just wanted to say thank you so much for everything, i just have this last Problem and I probably will figure it out later... Thanks' I realy aprechiate your help! could not have done it without you.

[Barand]

have you tried

 

$qt=mysql_query("select * from miv ORDER BY miv_datum LIMIT ($count-52), 52") or die(mysql_error());

[Barand]

I just did a quick test. You need to precalculate the start position.

 

$start = $count-52;

$qt=mysql_query("select * from miv ORDER BY miv_datum LIMIT $start, 52");

[rilana]

Wow thanks a lot! that last one worked!!! cool! thank you