Hola a todos!, wueno tengo un problema que por lo visto a mucha gente le sucede, quiero aprender ha utiilizar graficos jpgraph y para ello me he bajado un codigo de ejemplo de internet, despues he activado las extensiones php.ini para la libreria gd2.dll y he colocado correctamente la libreria del jpgraph, sin embargo me muestra el siguiente mensaje de error:
JpGraph Error: HTTP headers have already been sent.
Caused by output from file prova_grafica.php at line 8.
Explanation:
HTTP headers have already been sent back to the browser indicating the data as text before the library got a chance to send it's image HTTP header to this browser. This makes it impossible for the library to send back image data to the browser (since that would be interpretated as text by the browser and show up as junk text).
Most likely you have some text in your script before the call to Graph::Stroke(). If this texts gets sent back to the browser the browser will assume that all data is plain text. Look for any text, even spaces and newlines, that might have been sent back to the browser.
For example it is a common mistake to leave a blank line before the opening "<?php".
Por lo que he leido hay personas que lo resuleven borrando "una linea blanca" intermedia...yo las he borrado todas y sigue dando ese error, haber si alguien le sucedio un problema similar y me puede orientar un poco porfavor, aqui teneis el codigo:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Documento sin título</title>
</head>
<body>
<?php
include("jpgraph.php");
include("jpgraph_line.php");
$ydata = array(11, 3, 8, 12, 5, 1, 9, 13, 5, 7);
$graph = new Graph(350, 250, "auto");
$graph->SetScale("textlin");
$lineplot = new LinePlot($ydata);
$lineplot->SetColor("blue");
$graph->Add($lineplot);
$graph->Stroke();
?>
</body>
</html>
