LogisticRegression::LogisticRegression(DataMatrix<double> ddata, std::vector<double> iinit, double aalpha):
    data(ddata), init(iinit), alpha(aalpha), nrows(ddata.getRows()), ncols(ddata.getCols()){
    if(init.size() != (ncols-1))
        std::cerr<<"Error!"<<std::endl;
}