"0 at boundary/stable" specifies that where the function is stable or at the boundaries, the initial function should be overruled to have value 0.
f'_0(x) is initial velocity, which is ignored by the heat equation.
s: (x,y)->stable? is a function that specifies where the function must be held stable (not including the simulation boundaries, which can be held stable with a following option).
"Set initial from above definitions" resets the simulation to the initial conditions above. This updates your changes to the setup.
Realtime parameters:
You can adjust these as the simulation is running
At the top, you can switch between/realistic normal mode, as well as switch between which equation is being used. "Blend" lerps the velocities together using the factor following the button.
Stable boundary indicates whether the rectangular boundary of the simulation should be held still.
Finally, you can adjust the period and heat factor, which control how quickly each of the simulations is done. Be careful with your ranges of these.
Equations:
Multiplication must be done explicitly with '*' (as in x*y NOT xy).
Any javascript expression is a valid equation.
Special symbols are: sin, cos, tan, asin, acos, atan, sqrt, abs, exp, pow, max, min, pi, and, or, xor, not.
The stable function should return true (1) or false (0) for each position.