In[]:=
f[x_,y_]:=y;
In[]:=
regDef[x_,y_]:=(*Definetheregion*)If[(x^2+(y-1)^2<1)||(x^2+(y+1)^2<1),True,False];
In[]:=
data=Table[If[regDef[x,y],f[x,y],Sqrt[-1]],{x,-2,2,.02},{y,-2,+2,.02}];
In[]:=
Dimensions[data]
Out[]=
{201,201}
In[]:=
ListPlot3D[data,DataRange{{-2,2},{-2,2}}]
Out[]=
