$usespecgen is the command to put generation profile with a specific function, which is mostly Gaussian shape generation profile.
$usespecgen N_region func_type A B sigx, sigy, xc, yc
For function type
1: G(x,y)=A*B*exp(−(x−xc)2sigx2)*exp(−(y−yc)2sigy2) 2: G(x,y)=A*B*exp(−(x−xc)2sigx2)*exp(−(y−yc)2sigx2)*exp(−−|(y−yc)|sigy) 3: G(x,y)=A*B*exp(−(x−xc)2sigx2)*exp(−(y−yc)2sigx2)*exp(−−|(x−xc)|sigx) 4: G(x,y)=A*exp(−(x−xc)2sigx2)*exp(−(y−yc)2sigy2) 5: G(x,y)=A*exp(−(x−xc)2sigx2)*exp(−−|(y−yc)|sigy) 6: G(x,y)=A*exp(−(y−yc)2sigx2)*exp(−−|(x−xc)|sigx)