1 // -*- mode: C++; c-indent-level: 4; c-basic-offset: 4; indent-tabs-mode: nil; -*- 2 // 3 // lower_tri.h: Rcpp R/C++ interface class library -- lower.tri 4 // 5 // Copyright (C) 2010 - 2017 Dirk Eddelbuettel and Romain Francois 6 // Copyright (C) 2017 Dirk Eddelbuettel, Romain Francois, and Nathan Russell 7 // 8 // This file is part of Rcpp. 9 // 10 // Rcpp is free software: you can redistribute it and/or modify it 11 // under the terms of the GNU General Public License as published by 12 // the Free Software Foundation, either version 2 of the License, or 13 // (at your option) any later version. 14 // 15 // Rcpp is distributed in the hope that it will be useful, but 16 // WITHOUT ANY WARRANTY; without even the implied warranty of 17 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 // GNU General Public License for more details. 19 // 20 // You should have received a copy of the GNU General Public License 21 // along with Rcpp. If not, see <http://www.gnu.org/licenses/>. 22 23 #ifndef Rcpp__sugar__lower_tri_h 24 #define Rcpp__sugar__lower_tri_h 25 26 namespace Rcpp { 27 namespace sugar { 28 29 template <int RTYPE, bool NA, typename T> 30 class LowerTri : public MatrixBase<LGLSXP, false, LowerTri<RTYPE, NA, T> > { 31 public: 32 typedef Rcpp::MatrixBase<RTYPE, NA, T> MatBase; 33 LowerTri(const T & lhs,bool diag)34 LowerTri(const T& lhs, bool diag) 35 : nr(lhs.nrow()), 36 nc(lhs.ncol()), 37 getter(diag ? (&LowerTri::get_diag_true) : (&LowerTri::get_diag_false)) 38 {} 39 operator()40 inline int operator()(int i, int j) const { return get(i, j); } 41 size()42 inline R_xlen_t size() const { return static_cast<R_xlen_t>(nr) * nc; } nrow()43 inline int nrow() const { return nr; } ncol()44 inline int ncol() const { return nc; } 45 46 private: 47 typedef bool (LowerTri::*Method)(int, int) const; 48 49 int nr, nc; 50 Method getter; 51 get_diag_true(int i,int j)52 inline bool get_diag_true(int i, int j) const { return i >= j; } 53 get_diag_false(int i,int j)54 inline bool get_diag_false(int i, int j) const { return i > j; } 55 get(int i,int j)56 inline bool get(int i, int j) const { return (this->*getter)(i, j); } 57 }; 58 59 } // sugar 60 61 template <int RTYPE, bool NA, typename T> 62 inline sugar::LowerTri<RTYPE, NA, T> 63 lower_tri(const Rcpp::MatrixBase<RTYPE, NA, T>& lhs, bool diag = false) { 64 return sugar::LowerTri<RTYPE, NA, T>(lhs, diag); 65 } 66 67 } // Rcpp 68 69 #endif // Rcpp__sugar__lower_tri_h 70