1 | |
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2 | ! |
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3 | ! This program may be freely redistributed under the |
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4 | ! condition that the copyright notices (including this |
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5 | ! entire header) are not removed, and no compensation |
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6 | ! is received through use of the software. Private, |
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7 | ! research, and institutional use is free. You may |
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8 | ! distribute modified versions of this code UNDER THE |
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9 | ! CONDITION THAT THIS CODE AND ANY MODIFICATIONS MADE |
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10 | ! TO IT IN THE SAME FILE REMAIN UNDER COPYRIGHT OF THE |
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11 | ! ORIGINAL AUTHOR, BOTH SOURCE AND OBJECT CODE ARE |
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12 | ! MADE FREELY AVAILABLE WITHOUT CHARGE, AND CLEAR |
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13 | ! NOTICE IS GIVEN OF THE MODIFICATIONS. Distribution |
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14 | ! of this code as part of a commercial system is |
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15 | ! permissible ONLY BY DIRECT ARRANGEMENT WITH THE |
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16 | ! AUTHOR. (If you are not directly supplying this |
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17 | ! code to a customer, and you are instead telling them |
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18 | ! how they can obtain it for free, then you are not |
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19 | ! required to make any arrangement with me.) |
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20 | ! |
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21 | ! Disclaimer: Neither I nor: Columbia University, the |
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22 | ! National Aeronautics and Space Administration, nor |
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23 | ! the Massachusetts Institute of Technology warrant |
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24 | ! or certify this code in any way whatsoever. This |
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25 | ! code is provided "as-is" to be used at your own risk. |
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26 | ! |
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27 | ! |
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28 | |
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29 | ! |
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30 | ! UTIL1D.f90: util. func. for 1-dim. grid manipulation. |
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31 | ! |
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32 | ! Darren Engwirda |
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33 | ! 31-Mar-2019 |
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34 | ! de2363 [at] columbia [dot] edu |
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35 | ! |
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36 | ! |
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37 | |
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38 | subroutine linspace(xxll,xxuu,npos,xpos) |
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39 | |
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40 | ! |
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41 | ! XXLL lower-bound grid position. |
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42 | ! NNEW upper-bound grid position. |
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43 | ! NPOS no. edges in the grid. |
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44 | ! XPOS array of grid edges. XPOS has length NPOS . |
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45 | ! |
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46 | |
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47 | implicit none |
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48 | |
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49 | real*8 , intent(in) :: xxll,xxuu |
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50 | integer, intent(in) :: npos |
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51 | real*8 , intent(out) :: xpos(:) |
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52 | |
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53 | integer :: ipos |
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54 | real*8 :: xdel |
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55 | |
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56 | xpos( 1) = xxll |
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57 | xpos(npos) = xxuu |
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58 | |
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59 | xdel = (xxuu-xxll) / (npos - 1) |
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60 | |
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61 | do ipos = +2, npos-1 |
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62 | |
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63 | xpos(ipos) = (ipos-1) * xdel |
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64 | |
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65 | end do |
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66 | |
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67 | return |
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68 | |
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69 | end subroutine |
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70 | |
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71 | subroutine rndspace(xxll,xxuu,npos,xpos, & |
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72 | & frac) |
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73 | |
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74 | ! |
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75 | ! XXLL lower-bound grid position. |
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76 | ! NNEW upper-bound grid position. |
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77 | ! NPOS no. edges in the grid. |
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78 | ! XPOS array of grid edges. XPOS has length NPOS . |
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79 | ! FRAC fractional perturbation of cell, OPTIONAL . |
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80 | ! |
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81 | |
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82 | implicit none |
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83 | |
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84 | real*8 , intent(in) :: xxll,xxuu |
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85 | integer, intent(in) :: npos |
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86 | real*8 , intent(out) :: xpos(:) |
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87 | real*8 , intent(in), optional :: frac |
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88 | |
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89 | integer :: ipos |
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90 | real*8 :: xdel,rand,move |
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91 | |
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92 | if (present(frac)) then |
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93 | move = +frac |
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94 | else |
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95 | move = 0.33d0 |
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96 | end if |
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97 | |
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98 | xpos( 1) = xxll |
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99 | xpos(npos) = xxuu |
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100 | |
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101 | xdel = (xxuu-xxll) / (npos - 1) |
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102 | |
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103 | do ipos = +2, npos-1 |
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104 | |
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105 | xpos(ipos) = (ipos-1) * xdel |
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106 | |
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107 | end do |
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108 | |
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109 | do ipos = +2, npos-1 |
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110 | |
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111 | call random_number (rand) |
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112 | |
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113 | rand = 2.d0 * (rand-.5d0) |
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114 | |
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115 | move = rand * move |
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116 | |
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117 | xpos(ipos) = & |
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118 | & xpos(ipos) + move * xdel |
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119 | |
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120 | end do |
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121 | |
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122 | return |
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123 | |
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124 | end subroutine |
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125 | |
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126 | |
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127 | |
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