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1 The Fractal Realizer |
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2 May 25, 2007 |
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3 |
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4 The Fractal Realizer has been rewritten in Fortran-90. There are |
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5 no longer any pieces of code in C. The visualization feature (using |
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6 DrawPixmap) has been eliminated, since maps can be viewed as XPM files |
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7 after running the model. The new code has been compiled and tested |
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8 with gfortran under Linux on an Athlon-64 box. Example scripts and |
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9 data are available in directories below examples/. The code is in |
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10 the src/ directory. The previous README file is still included here |
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11 as README.previous. |
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12 |
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13 Installation |
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14 ------------ |
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15 If you are using gfortran under Linux, simply do the following to build |
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16 and install the Fractal Realizer. Download the code and examples: |
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17 |
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18 $ wget http://www.geobabble.org/~hnw/frdist.90 |
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19 |
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20 Then extract the code and examples: |
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21 |
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22 $ tar xvzf frdist90.tar.gz |
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23 |
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24 Next, build the code: |
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25 |
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26 $ cd frdist90/src |
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27 $ make |
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28 |
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29 This will produce the binary program called realizer. To install the |
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30 Fractal Realizer in /usr/local/bin: |
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31 |
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32 $ sudo make install |
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33 |
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34 Execution |
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35 --------- |
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36 |
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37 The Fractal Realizer has many options, and some of these are mutually |
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38 exclusive. Simply running the executable begins a cascade of questions |
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39 from the model which query the user to set up the options for the |
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40 simulation run. Responses to the questions direct the subsequent |
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41 questions, changing the way that the option tree is traversed. This |
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42 verbose interaction mode is a good way to become familiar with the wide |
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43 array of Fractal Realizer options. After all questions are answered, |
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44 the simulation begins. |
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45 |
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46 Because answering all of the input questions for each run would be |
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47 tedious, the Fractal Realizer writes a script file, inpout.scr, containing |
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48 the input answers from the last run. Thus, the last simulation can be |
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49 repeated by issuing the command: |
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50 |
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51 $ realizer < input.scr |
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52 |
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53 To change a few input settings, it is not necessary to wade through all |
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54 of the input questions again. Instead, simply edit the input.scr script |
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55 file directly, and then re-run the simulation using the modified script |
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56 file. Mnemonic comments within the script file aid in such editing |
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57 process. |
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58 |
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59 A number of demonstration .scr script files are included in the in the |
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60 examples/ directory, and running these "canned" examples is a good way to |
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61 test the installation, as well as to see the capabilities of the Fractal |
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62 Realizer. Final landscapes and tie maps can be output in several formats, |
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63 including XPM and GRASS. |
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64 |
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65 The FR program uses a heap sort to sort the entire map to find the |
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66 highest probability sites, so execution time will increase rapidly as |
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67 the size of the map is increased. Execution time also increases with |
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68 increasing numbers of categories in the map. Because of the midpoint |
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69 displacement algorithm for generating (pseudo)fractals, the maps must |
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70 be square, with sides of (2**n)+1. However, the use of constraint masks |
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71 will permit oddly-shaped and smaller synthetic maps to be generated |
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72 while still preserving both p and the fractal dimension of each category. |
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73 |
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74 The Fractal Realizer has proven useful and stimulating. Be sure |
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75 to read and cite our paper in Conservation Ecology available at |
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76 http://www.ecologyandsociety.org/vol6/iss1/art2/ |
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77 |
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78 Bill and Forrest |
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79 ------------------------------------------------------------------------------- |
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80 William W. Hargrove |
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81 Eastern Forest Environmental Threat Assessment Center |
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82 USDA Forest Service |
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83 Southern Research Station |
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84 200 WT Weaver Boulevard |
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85 Asheville, NC 28804-3454 |
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86 ------------------------------------------------------------------------------- |
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87 Forrest Hoffman mailto:forrest@climatemodeling.org |
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88 Oak Ridge National Laboratory mailto:forrest@computer.org |
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89 Climate & Carbon Research Institute http://www.climatemodeling.org/~forrest |
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90 Computer Science & Mathematics Div. (865) 576-7680 voice |
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91 Building 5600, Room C221, MS 6016 (865) 576-5491 fax |
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92 P.O. Box 2008 Deliveries: Bethel Valley Road |
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93 Oak Ridge TN 37831-6016 35� 55' 23" N 84� 19' 20" W |
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94 ------------------------------------------------------------------------------- |