Arduino Radar Project Problems

Hey guys, I'm new to Arduino and I'm doing a project at school making an Arduino radar. I've found some code for the project but the maker made his own function called "pushMatrix"...
When compiling the code it says 2 error messages.
• 'pushMatrix' was not declared in this scope
• 'pushMatrix' cannot be used as a function

Does anyone know why this happens or how to fix it??
There are many different piece of code required for the project, so here's the link to the website I used...

The pushMatrix function is part of the Processing code for visualizing the data on the PC, it is not Arduino code. If you scroll down the page the complete Processing code is given.

Where do I put the processing code if it is not Arduino?? Is there another program or website I type it into??

TheOneDarkEye:
Where do I put the processing code if it is not Arduino?? Is there another program or website I type it into??

Processing runs on the PC.
It's Java.

So PDE would run processing code??

TheOneDarkEye:
So PDE would run processing code??

No, a .pde is Processing code.

I linked the Processing web site. If you go there you can learn all about Processing.

Processing runs PDE files.

So...
PDE is its own coding language...
Arduino is its own code an it uses the Arduino program to run it. What would I use to run PDE??

This is very confusing...

PDE is its own coding language

No, PDE is a file extension.
The file contents are Java.

Java runs on a Java-capable platform, like a PC.