From: antonello on
Hello,
I would plot a 3d function defined differently in the four quadrants.
first quadrant= f(z)=ax+by,second quadrant f(z)=sen(x+y) etc etc
I thought I'd write four meshgrid instructions, one for each defined domain but what instructions should I use for plotting on the same graph this function defined on the 4 quadrants?
Could someone kindly help me?

thx!