rowvec star(const rowvec& vphi, const umat& vxicat){
	rowvec vphis = vphi;
	umat::const_iterator iter = vxicat.begin();
	int len = vxicat.n_elem;
	int L = vphi.n_elem/2/len;
	for(int i=0; i< len; i++){
		for(int l=(*iter);l<L;l++){
			vphis[l*len+i] = 0;
			vphis[(l+L)*len+i] = 0;
		}
		iter++;
	}
	return vphis;
}