subroutine char F_MASK int M_MASK int M_ORIG int M_DENS

read file F_MASK map xpl over M_MASK
make map M_MASK from M_ORIG \
    rota matr MAT_ROT \
    tran vect XTRAN YTRAN ZTRAN \
    center coor 0 0 0 
make map M_DENS from M_MASK  add
return