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Diffstat (limited to 'graphics/epix/interval.cc')
| -rw-r--r-- | graphics/epix/interval.cc | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/graphics/epix/interval.cc b/graphics/epix/interval.cc new file mode 100644 index 0000000000..11f7a2aace --- /dev/null +++ b/graphics/epix/interval.cc @@ -0,0 +1,228 @@ +/* + * interval.cc -- ePiX::interval class functions + * + * This file is part of ePiX, a C++ library for creating high-quality + * figures in LaTeX + * + * Version 1.2.0-2 + * Last Change: September 26, 2007 + * + * + * Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007 + * Andrew D. Hwang <rot 13 nujnat at zngupf dot ubylpebff dot rqh> + * Department of Mathematics and Computer Science + * College of the Holy Cross + * Worcester, MA, 01610-2395, USA + * + * + * ePiX is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * ePiX is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public + * License for more details. + * + * You should have received a copy of the GNU General Public License + * along with ePiX; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ +#include <cstdlib> +#include <string> + +#include "functions.h" +#include "interval.h" + +namespace ePiX { + + // expect arg of the form (a,b), [a,b), (a,b], or [a,b] + interval::interval(std::string arg) + : m_closed_l(true), m_closed_r(true) + { + std::string::size_type i(arg.find_first_of("[(")); + + if (i == std::string::npos) // return "empty interval" + { + m_rmin=1; + m_rmax=0; + return; + } + + // else + arg.erase(0, i); + + if (arg.at(0) == '(') + m_closed_l = false; + + // expect numerical argument + i = arg.find_first_of("-0123456789."); + if (i == std::string::npos) + { + m_rmin=1; + m_rmax=0; + return; + } + + arg.erase(0, i); + + // get left endpoint + const char* tmp1(arg.c_str()); + char* new_arg; + m_rmin = strtod(tmp1, &new_arg); + arg=new_arg; + + i = arg.find_first_of(","); + if (i == std::string::npos) + { + m_rmax=0; + m_rmin=1; + return; + } + + arg.erase(0, i); + + // expect another numerical argument + i = arg.find_first_of("-0123456789."); + if (i == std::string::npos) + { + m_rmax=0; + m_rmin=1; + return; + } + + arg.erase(0, i); + + const char* tmp2(arg.c_str()); + m_rmax = strtod(tmp2, &new_arg); + arg=new_arg; + + i = arg.find_first_of(")]"); + + if (i == std::string::npos) + { + m_rmax=0; + m_rmin=1; + return; + } + + if (arg.at(0) == ')') + m_closed_r = false; + } // end of interval(std::string) + + + interval::interval(double a, double b) + : m_rmin(ePiX::min(a, b)), m_rmax(ePiX::max(a, b)), + m_closed_l(true), m_closed_r(true) { } + + interval interval::literal(double a, double b) + { + interval value(a, a); + value.m_rmax = b; + return value; + } + + interval interval::emptyset(literal(1,0)); + + double interval::min() const + { + return m_rmin; + } + + double interval::max() const + { + return m_rmax; + } + + double interval::avg() const + { + return 0.5*(m_rmin + m_rmax); + } + + + // Magic number + const double EPS(1.0e-10); + + bool interval::contains(double x) const + { + // check bounds at each endpoint + return ( (m_closed_l ? (m_rmin - EPS <= x) : (m_rmin + EPS < x)) + && (m_closed_r ? (x <= m_rmax + EPS) : (x < m_rmax - EPS)) ); + } + + // Minkowski sum + interval& interval::operator +=(const interval& I) + { + if (is_empty()) + ; + + else if (I.is_empty()) + *this = interval::emptyset; + + else + { + m_rmin += I.m_rmin; + m_rmax += I.m_rmax; + + // sum contains endpoint iff both arguments do + m_closed_l &= I.m_closed_l; + m_closed_r &= I.m_closed_r; + } + + return *this; + } + + // intersection + interval& interval::operator *=(const interval& I) + { + if (!is_empty()) + { + m_rmin = ePiX::max(m_rmin, I.m_rmin); + m_rmax = ePiX::min(m_rmax, I.m_rmax); + + m_closed_l &= I.m_closed_l; + m_closed_r &= I.m_closed_r; + } + + return *this; + } + + bool interval::operator== (const interval& I) const + { + if (is_empty()) + return (I.is_empty()); // both empty? + + else + return ((m_rmin == I.m_rmin) && (m_rmax == I.m_rmax) + && (m_closed_l == I.m_closed_l) && (m_closed_r == I.m_closed_r)); + } + + bool interval::operator!= (const interval& I) const + { + return !(*this == I); + } + + bool interval::is_empty() const + { + if ( (m_rmin < m_rmax) + || ( (m_rmin == m_rmax) && m_closed_l && m_closed_r ) ) + return false; + + else + return true; + } + + // non-members + interval operator+ (interval I1, const interval& I2) + { + return I1 += I2; + } + + interval operator* (interval I1, const interval& I2) + { + return I1 *= I2; + } + +} // end of namespace |