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1 /* |
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2 |
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3 Copyright (C) 1996, 1997 John W. Eaton |
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4 |
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5 This file is part of Octave. |
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6 |
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7 Octave is free software; you can redistribute it and/or modify it |
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8 under the terms of the GNU General Public License as published by the |
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9 Free Software Foundation; either version 2, or (at your option) any |
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10 later version. |
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11 |
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12 Octave is distributed in the hope that it will be useful, but WITHOUT |
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13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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15 for more details. |
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16 |
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17 You should have received a copy of the GNU General Public License |
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18 along with Octave; see the file COPYING. If not, write to the Free |
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19 Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
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20 02110-1301, USA. |
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21 |
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22 */ |
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23 |
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24 #ifdef HAVE_CONFIG_H |
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25 #include <config.h> |
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26 #endif |
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27 |
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28 #include <cfloat> |
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29 #include <cmath> |
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30 |
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31 #include "dbleDET.h" |
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32 #include "lo-mappers.h" |
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33 |
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34 bool |
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35 DET::value_will_overflow (void) const |
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36 { |
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37 return base2 |
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38 ? (e2 + 1 > xlog2 (DBL_MAX) ? 1 : 0) |
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39 : (e10 + 1 > log10 (DBL_MAX) ? 1 : 0); |
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40 } |
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41 |
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42 bool |
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43 DET::value_will_underflow (void) const |
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44 { |
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45 return base2 |
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46 ? (e2 - 1 < xlog2 (DBL_MIN) ? 1 : 0) |
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47 : (e10 - 1 < log10 (DBL_MIN) ? 1 : 0); |
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48 } |
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49 |
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50 void |
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51 DET::initialize10 (void) |
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52 { |
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53 if (c2 != 0.0) |
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54 { |
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55 double etmp = e2 / xlog2 (10); |
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56 e10 = static_cast<int> (xround (etmp)); |
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57 etmp -= e10; |
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58 c10 = c2 * pow (10.0, etmp); |
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59 } |
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60 } |
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61 |
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62 void |
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63 DET::initialize2 (void) |
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64 { |
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65 if (c10 != 0.0) |
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66 { |
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67 double etmp = e10 / log10 (2); |
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68 e2 = static_cast<int> (xround (etmp)); |
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69 etmp -= e2; |
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70 c2 = c10 * xexp2 (etmp); |
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71 } |
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72 } |
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73 |
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74 double |
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75 DET::value (void) const |
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76 { |
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77 return base2 ? c2 * xexp2 (e2) : c10 * pow (10.0, e10); |
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78 } |
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79 |
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80 /* |
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81 ;;; Local Variables: *** |
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82 ;;; mode: C++ *** |
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83 ;;; End: *** |
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84 */ |
