PHP - RRD rrd_graph() Function

The PHP RRD rrd_graph() function is used to generate graphs and charts from RRD data. By creating visual representations of time-series data, like performance metrics or logs, it makes the examination of trends and patterns easily.

Syntax

Below is the syntax of the PHP RRD rrd_graph() function −

int rrd_graph ( string $filename , array $options )

Parameters

Below are the parameters of the rrd_graph() function −

• $filename − It is the name of the file where the graph will be printed. This will usually finish in .png, .svg, or .eps, depending on the format you wish to use.

• $options − It is the options for creating images. All choices (data definitions, variable definitions, etc.) are acceptable.

Return Value

The rrd_graph() function returns array with information about generated image on success and FALSE on failure.

PHP Version

The rrd_graph() function is available from version 0.9.0 of the PECL rrd extension onwards.

Example 1

First we will show you the basic example of the PHP RRD rrd_graph() function to creates a simple graph from an RRD database.

<?php
   // Path to the RRD file
   $filename = "/PHP/PhpProjetcs/image.png";
   
   // Options for the graph
   $options = array(
       "--imgformat", "PNG",
       "--width", "300",
       "--height", "200",
       "--title", "Basic Graph",
       "DEF:mydata=example.rrd:your_data:AVERAGE",
       "LINE1:mydata#FF0000:My Data"
   );
   
   // Generate the graph
   $result = rrd_graph($filename, $options);
   
   if ($result == 0) {
       echo "Graph created successfully!";
   } else {
       echo "Failed to create graph.";
   }   
?>

Output

The above code will result something like this −

Graph created successfully!

Example 2

In the below PHP code we will try to use the rrd_graph() function and create a line graph which has data from multiple sources.

<?php
   // Specify the filename
   $filename = "multi_line_graph.png";
   
   $options = array(
       "--imgformat", "PNG",
       "--width", "500",
       "--height", "300",
       "--title", "Multi-Line Graph",
       "DEF:data1=example.rrd:source1:AVERAGE",
       "DEF:data2=example.rrd:source2:AVERAGE",
       "LINE1:data1#00FF00:Data Source 1",
       "LINE2:data2#0000FF:Data Source 2"
   );
   
   $result = rrd_graph($filename, $options);
   
   if ($result == 0) {
       echo "The multi-line graph has been created!";
   } else {
       echo "Failed to create multi-line graph.";
   }
   ?>
   
?> 

Output

After running the above program, it generates the following output −

The multi-line graph has been created!