Mercurial > octave
view libinterp/octave-value/ov-legacy-range.cc @ 31608:23664317f0d3
maint: merge stable to default
author | Rik <rik@octave.org> |
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date | Thu, 01 Dec 2022 20:05:44 -0800 |
parents | fb77a0b4a00a aac27ad79be6 |
children | 5f11de0e7440 |
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//////////////////////////////////////////////////////////////////////// // // Copyright (C) 1996-2022 The Octave Project Developers // // See the file COPYRIGHT.md in the top-level directory of this // distribution or <https://octave.org/copyright/>. // // This file is part of Octave. // // Octave 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 3 of the License, or // (at your option) any later version. // // Octave 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 Octave; see the file COPYING. If not, see // <https://www.gnu.org/licenses/>. // //////////////////////////////////////////////////////////////////////// #if defined (HAVE_CONFIG_H) # include "config.h" #endif #include <istream> #include <ostream> #include <sstream> #include "Range.h" #include "lo-ieee.h" #include "lo-utils.h" #include "variables.h" #include "error.h" #include "ovl.h" #include "oct-hdf5.h" #include "ov-legacy-range.h" #include "ov-range.h" #include "ov-re-mat.h" #include "ov-scalar.h" #include "pr-output.h" #include "byte-swap.h" #include "ls-ascii-helper.h" #include "ls-hdf5.h" #include "ls-utils.h" class Range { public: Range (void) : m_base (0), m_limit (0), m_inc (0), m_numel (0) { } // Assume range is already properly constructed, so just copy internal // values. However, we set LIMIT to the computed final value because // that mimics the behavior of the other Range class constructors that // reset limit to the computed final value. Range (const octave::range<double>& r) : m_base (r.base ()), m_limit (r.final_value ()), m_inc (r.increment ()), m_numel (r.numel ()) { } Range (const Range& r) = default; Range& operator = (const Range& r) = default; ~Range (void) = default; Range (double b, double l) : m_base (b), m_limit (l), m_inc (1), m_numel (numel_internal ()) { if (! octave::math::isinf (m_limit)) m_limit = limit_internal (); } Range (double b, double l, double i) : m_base (b), m_limit (l), m_inc (i), m_numel (numel_internal ()) { if (! octave::math::isinf (m_limit)) m_limit = limit_internal (); } // The range has a finite number of elements. bool ok (void) const { return (octave::math::isfinite (m_limit) && (m_numel >= 0 || m_numel == -2)); } double base (void) const { return m_base; } double limit (void) const { return m_limit; } double increment (void) const { return m_inc; } octave_idx_type numel (void) const { return m_numel; } bool all_elements_are_ints (void) const; Matrix matrix_value (void) const; double min (void) const; double max (void) const; private: double m_base; double m_limit; double m_inc; octave_idx_type m_numel; octave_idx_type numel_internal (void) const; double limit_internal (void) const; void init (void); }; bool Range::all_elements_are_ints (void) const { // If the base and increment are ints, the final value in the range will also // be an integer, even if the limit is not. If there is one or fewer // elements only the base needs to be an integer. return (! (octave::math::isnan (m_base) || octave::math::isnan (m_inc)) && (octave::math::nint_big (m_base) == m_base || m_numel < 1) && (octave::math::nint_big (m_inc) == m_inc || m_numel <= 1)); } Matrix Range::matrix_value (void) const { Matrix retval (1, m_numel); if (m_numel > 0) { // The first element must always be *exactly* the base. // E.g, -0 would otherwise become +0 in the loop (-0 + 0*increment). retval(0) = m_base; double b = m_base; double increment = m_inc; for (octave_idx_type i = 1; i < m_numel - 1; i++) retval.xelem (i) = b + i * increment; retval.xelem (m_numel - 1) = m_limit; } return retval; } // NOTE: max and min only return useful values if numel > 0. // do_minmax_body() in max.cc avoids calling Range::min/max if numel == 0. double Range::min (void) const { double retval = 0.0; if (m_numel > 0) { if (m_inc > 0) retval = m_base; else { retval = m_base + (m_numel - 1) * m_inc; // Require '<=' test. See note in max (). if (retval <= m_limit) retval = m_limit; } } return retval; } double Range::max (void) const { double retval = 0.0; if (m_numel > 0) { if (m_inc > 0) { retval = m_base + (m_numel - 1) * m_inc; // On some machines (x86 with extended precision floating point // arithmetic, for example) it is possible that we can overshoot the // limit by approximately the machine precision even though we were // very careful in our calculation of the number of elements. // Therefore, we clip the result to the limit if it overshoots. // The test also includes equality (>= m_limit) to have expressions // such as -5:1:-0 result in a -0 endpoint. if (retval >= m_limit) retval = m_limit; } else retval = m_base; } return retval; } // C See Knuth, Art Of Computer Programming, Vol. 1, Problem 1.2.4-5. // C // C===Tolerant FLOOR function. // C // C X - is given as a Double Precision argument to be operated on. // C It is assumed that X is represented with M mantissa bits. // C CT - is given as a Comparison Tolerance such that // C 0.LT.CT.LE.3-SQRT(5)/2. If the relative difference between // C X and A whole number is less than CT, then TFLOOR is // C returned as this whole number. By treating the // C floating-point numbers as a finite ordered set note that // C the heuristic EPS=2.**(-(M-1)) and CT=3*EPS causes // C arguments of TFLOOR/TCEIL to be treated as whole numbers // C if they are exactly whole numbers or are immediately // C adjacent to whole number representations. Since EPS, the // C "distance" between floating-point numbers on the unit // C interval, and M, the number of bits in X'S mantissa, exist // C on every floating-point computer, TFLOOR/TCEIL are // C consistently definable on every floating-point computer. // C // C For more information see the following references: // C (1) P. E. Hagerty, "More On Fuzzy Floor And Ceiling," APL QUOTE // C QUAD 8(4):20-24, June 1978. Note that TFLOOR=FL5. // C (2) L. M. Breed, "Definitions For Fuzzy Floor And Ceiling", APL // C QUOTE QUAD 8(3):16-23, March 1978. This paper cites FL1 through // C FL5, the history of five years of evolutionary development of // C FL5 - the seven lines of code below - by open collaboration // C and corroboration of the mathematical-computing community. // C // C Penn State University Center for Academic Computing // C H. D. Knoble - August, 1978. static inline double tfloor (double x, double ct) { // C---------FLOOR(X) is the largest integer algebraically less than // C or equal to X; that is, the unfuzzy FLOOR function. // DINT (X) = X - DMOD (X, 1.0); // FLOOR (X) = DINT (X) - DMOD (2.0 + DSIGN (1.0, X), 3.0); // C---------Hagerty's FL5 function follows... double q = 1.0; if (x < 0.0) q = 1.0 - ct; double rmax = q / (2.0 - ct); double t1 = 1.0 + std::floor (x); t1 = (ct / q) * (t1 < 0.0 ? -t1 : t1); t1 = (rmax < t1 ? rmax : t1); t1 = (ct > t1 ? ct : t1); t1 = std::floor (x + t1); if (x <= 0.0 || (t1 - x) < rmax) return t1; else return t1 - 1.0; } static inline bool teq (double u, double v, double ct = 3.0 * std::numeric_limits<double>::epsilon ()) { double tu = std::abs (u); double tv = std::abs (v); return std::abs (u - v) < ((tu > tv ? tu : tv) * ct); } octave_idx_type Range::numel_internal (void) const { octave_idx_type retval = -1; if (! octave::math::isfinite (m_base) || ! octave::math::isfinite (m_inc) || octave::math::isnan (m_limit)) retval = -2; else if (octave::math::isinf (m_limit) && ((m_inc > 0 && m_limit > 0) || (m_inc < 0 && m_limit < 0))) retval = std::numeric_limits<octave_idx_type>::max () - 1; else if (m_inc == 0 || (m_limit > m_base && m_inc < 0) || (m_limit < m_base && m_inc > 0)) { retval = 0; } else { double ct = 3.0 * std::numeric_limits<double>::epsilon (); double tmp = tfloor ((m_limit - m_base + m_inc) / m_inc, ct); octave_idx_type n_elt = (tmp > 0.0 ? static_cast<octave_idx_type> (tmp) : 0); // If the final element that we would compute for the range is equal to // the limit of the range, or is an adjacent floating point number, // accept it. Otherwise, try a range with one fewer element. If that // fails, try again with one more element. // // I'm not sure this is very good, but it seems to work better than just // using tfloor as above. For example, without it, the expression // 1.8:0.05:1.9 fails to produce the expected result of [1.8, 1.85, 1.9]. if (! teq (m_base + (n_elt - 1) * m_inc, m_limit)) { if (teq (m_base + (n_elt - 2) * m_inc, m_limit)) n_elt--; else if (teq (m_base + n_elt * m_inc, m_limit)) n_elt++; } retval = ((n_elt < std::numeric_limits<octave_idx_type>::max ()) ? n_elt : -1); } return retval; } double Range::limit_internal (void) const { double new_limit = m_inc > 0 ? max () : min (); // If result must be an integer then force the new_limit to be one. if (all_elements_are_ints ()) new_limit = std::round (new_limit); return new_limit; } void Range::init (void) { m_numel = numel_internal (); if (! octave::math::isinf (m_limit)) m_limit = limit_internal (); } DEFINE_OV_TYPEID_FUNCTIONS_AND_DATA (octave_legacy_range, "range", "double"); octave_legacy_range::octave_legacy_range (void) : octave_base_value (), m_range (new Range ()) { } octave_legacy_range::octave_legacy_range (const Range& r) : octave_base_value (), m_range (new Range (r)) { if (m_range->numel () < 0 && m_range->numel () != -2) error ("invalid range"); } octave_legacy_range::octave_legacy_range (const octave_legacy_range& r) : octave_base_value (r), m_range () { m_range.reset (new Range (*(r.m_range))); } static octave_base_value * default_numeric_conversion_function (const octave_base_value& a) { const octave_legacy_range& v = dynamic_cast<const octave_legacy_range&> (a); return new octave_matrix (v.matrix_value ()); } octave_base_value::type_conv_info octave_legacy_range::numeric_conversion_function (void) const { return octave_base_value::type_conv_info (default_numeric_conversion_function, octave_matrix::static_type_id ()); } octave_base_value * octave_legacy_range::try_narrowing_conversion (void) { octave_base_value *retval = nullptr; switch (m_range->numel ()) { case 1: retval = new octave_scalar (m_range->base ()); break; case 0: retval = new octave_matrix (Matrix (1, 0)); break; case -2: retval = new octave_matrix (m_range->matrix_value ()); break; default: { if (m_range->increment () == 0) retval = new octave_matrix (m_range->matrix_value ()); else retval = new octave_range (octave::range<double> (m_range->base (), m_range->increment (), m_range->limit (), m_range->numel ())); } break; } return retval; } // Skip white space and comments on stream IS. static void skip_comments (std::istream& is) { char c = '\0'; while (is.get (c)) { if (c == ' ' || c == '\t' || c == '\n') ; // Skip whitespace on way to beginning of next line. else break; } octave::skip_until_newline (is, false); } bool octave_legacy_range::load_ascii (std::istream& is) { // # base, limit, range comment added by save (). skip_comments (is); double base, limit, inc; is >> base >> limit >> inc; if (! is) error ("load: failed to load range constant"); if (inc != 0) m_range.reset (new Range (base, limit, inc)); else m_range.reset (new Range (base, inc, static_cast<octave_idx_type> (limit))); return true; } bool octave_legacy_range::load_binary (std::istream& is, bool swap, octave::mach_info::float_format /* fmt */) { char tmp; if (! is.read (reinterpret_cast<char *> (&tmp), 1)) return false; double bas, lim, inc; if (! is.read (reinterpret_cast<char *> (&bas), 8)) return false; if (swap) swap_bytes<8> (&bas); if (! is.read (reinterpret_cast<char *> (&lim), 8)) return false; if (swap) swap_bytes<8> (&lim); if (! is.read (reinterpret_cast<char *> (&inc), 8)) return false; if (swap) swap_bytes<8> (&inc); if (inc != 0) m_range.reset (new Range (bas, lim, inc)); else m_range.reset (new Range (bas, inc, static_cast<octave_idx_type> (lim))); return true; } #if defined (HAVE_HDF5) // The following subroutines creates an HDF5 representation of the way // we will store Octave range types (triplets of floating-point numbers). // NUM_TYPE is the HDF5 numeric type to use for storage (e.g. // H5T_NATIVE_DOUBLE to save as 'double'). Note that any necessary // conversions are handled automatically by HDF5. static hid_t hdf5_make_range_type (hid_t num_type) { hid_t type_id = H5Tcreate (H5T_COMPOUND, sizeof (double) * 3); H5Tinsert (type_id, "base", 0 * sizeof (double), num_type); H5Tinsert (type_id, "limit", 1 * sizeof (double), num_type); H5Tinsert (type_id, "increment", 2 * sizeof (double), num_type); return type_id; } #endif bool octave_legacy_range::load_hdf5 (octave_hdf5_id loc_id, const char *name) { bool retval = false; #if defined (HAVE_HDF5) #if defined (HAVE_HDF5_18) hid_t data_hid = H5Dopen (loc_id, name, octave_H5P_DEFAULT); #else hid_t data_hid = H5Dopen (loc_id, name); #endif hid_t type_hid = H5Dget_type (data_hid); hid_t range_type = hdf5_make_range_type (H5T_NATIVE_DOUBLE); if (! hdf5_types_compatible (type_hid, range_type)) { H5Tclose (range_type); H5Dclose (data_hid); return false; } hid_t space_hid = H5Dget_space (data_hid); hsize_t rank = H5Sget_simple_extent_ndims (space_hid); if (rank != 0) { H5Tclose (range_type); H5Sclose (space_hid); H5Dclose (data_hid); return false; } double rangevals[3]; if (H5Dread (data_hid, range_type, octave_H5S_ALL, octave_H5S_ALL, octave_H5P_DEFAULT, rangevals) >= 0) { retval = true; octave_idx_type nel; if (hdf5_get_scalar_attr (data_hid, H5T_NATIVE_IDX, "OCTAVE_RANGE_NELEM", &nel)) m_range.reset (new Range (rangevals[0], rangevals[2], nel)); else { if (rangevals[2] != 0) m_range.reset (new Range (rangevals[0], rangevals[1], rangevals[2])); else m_range.reset (new Range (rangevals[0], rangevals[2], static_cast<octave_idx_type> (rangevals[1]))); } } H5Tclose (range_type); H5Sclose (space_hid); H5Dclose (data_hid); #else octave_unused_parameter (loc_id); octave_unused_parameter (name); warn_load ("hdf5"); #endif return retval; }