You will need the 'pcre' and 'gd' PHP modules in both your command-line and server-side (mod_php/ISAPI) PHP. The command-line tool runs using the command-line PHP, and the editor uses the server-side one. In some situations it is possible to have two completely different PHP installations serving these two - if you install from a package, then re-install from source, but to a different directory, for example. The editor and the CLI tool should both warn you if the part they need is not present.>
Before you start using it, you might want to change one PHP setting. Weathermap uses a fair bit of memory by PHP standards, as it builds the image for the map in memory before saving it. As a result, your PHP process may run out of memory. PHP has a 'safety valve' built-in, to stop runaway scripts from killing your server, which defaults to 8MB in most versions (this has changed in 5.2.x). This is controlled by the 'memory_limit =' line in php.ini. You may need to increase this to 32MB or even more if you have problems. These problems will typically show up as the process just dying with no warning or error message, as PHP kills the script.
Unpack the zip file into a directory somewhere. If you are intending to use the browser-based editor, then the directory that you unpack the zip file into should be within the 'web space' on the web server that runs your data-collection application (that is, Cacti, MRTG, or similar) - /var/www/html, /usr/local/www/data or whatever it is for you.
You'll need to edit two lines in the weathermap file:
from a shell or command prompt, and get a (rather boring) weathermap.png file in return. If you don't, you should get some kind of error to help you figure out why.
Once you have weathermap itself working, continue onto the editor:
Copy the editor-config.php-dist file to editor-config.php. If you use Cacti, and want to be able to pick data sources from your Cacti installation by name, edit the file and make sure that the line that sets $cacti_base is correct, and that the base URI below that is also correct for your Cacti installation (these two lines are marked CHANGE in the file).
Make sure that your webserver can write to the configs directory. To do this, you need to know which user your webserver runs as (maybe 'nobody', 'www' or 'httpd' on most *nixes) and then run:
chown www configs chmod u+w configs
On Windows, the same applies - the user that runs the webserver runs as should have permissions to write new files, and change existing files in the configs folder.
You should now be able to go to http://yourserver/wherever-you-unpacked-weathermap/editor.php in a browser, and get a welcome page that offers to load or create a config file. That's it. All done. Please see the editor manual page for more about using the editor!
Important Security Note: The editor allows anyone who can access editor.php to change the configuration files for your network weathermaps. There is no authentication built-in for editing, even with the Cacti Plugin. This is why the configuration file doesn't exist by default - the editor won't work until you choose to make it work. It's recommended that you either: