Solving 2 PDEs across one domain.

I am trying to model heat input to a small spot in the centre of a 'flat plate' domain (laser pulse). I can set up the geometry so that I have a circle inside a large square, but how do I set up/code the PDE(s) such that the heat input is only within this small circle, yet the pde is solved over the entire domain?

The pde is essentially the same across the entire domain apart from an additional heat input to elements inside the circle.

Many thanks.

P.S. I intend to vary/run over various parameters, so would appreciate answers that enable me to do it from the code as well as the pde gui.

[Jack]

Bill's answer separating the different domains with a ! was useful.

It also led me to this which helped: http://www.mathworks.com/matlabcentral/answers/93373-how-can-i-specify-different-pde-coefficients-or-different-equations-for-different-regions-using-the

Answer 1

[Bill Greene]

This documentation page shows how to specify an f-coefficient on a specific domain:

f-coefficient as a string expression