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2 | Quaternion toolbox for Matlab |
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3 | http://qtfm.sourceforge.net/ |
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4 | Mailing list: qtfm-announce@lists.sourceforge.net |
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5 | -------------------------------------------------------------- |
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6 | Copyright (©) Stephen J. Sangwine (S.Sangwine@IEEE.org) |
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7 | 2005, 2006 Nicolas Le Bihan (nicolas.le-bihan@lis.inpg.fr) |
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8 | -------------------------------------------------------------- |
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9 | |
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10 | Release Notes |
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11 | |
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12 | Version 1.0 14 December 2006 |
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13 | |
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14 | This release does not mark a major update to the toolbox, but |
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15 | reflects the fact that the previous version has now been in use |
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16 | for long enough for problems to come to light. The toolbox is |
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17 | now sufficiently mature to have a version number that does not |
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18 | start with zero. |
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19 | |
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20 | We have included with this release a new function svdj() which |
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21 | computes a singular value decomposition using a cyclic Jacobi |
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22 | algorithm. It will work on real and complex matrices as well |
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23 | as quaternion matrices. This code therefore demonstrates some |
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24 | of the tricks needed to write code that will work on real and |
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25 | complex matrices as well as quaternion matrices. We believe this |
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26 | may be a useful test feature. |
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27 | |
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28 | The Matlab functions ceil, floor, fix and round have been |
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29 | overloaded for quaternion matrices. |
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30 | |
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31 | Version 0.9 13 July 2006 |
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32 | |
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33 | The Matlab constructor function complex() has been overloaded |
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34 | for quaternions, making it possible to write complex(a, b), |
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35 | where one or both of a and b is a quaternion. |
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36 | |
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37 | The two Matlab functions conv and conv2 (convolution) have |
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38 | been overloaded for quaternions. |
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39 | |
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40 | A new function convert has been introduced to replace the |
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41 | previous functions double, single, uint8 etc. convert works |
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42 | on the elements of a quaternion, e.g. p = convert(q, 'single') |
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43 | results in a quaternion with single precision components. |
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44 | The previous functions have been removed as they cause Matlab |
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45 | to execute a statement like X(1,2) = quaternion(1,2,3,4) even |
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46 | though X is of type double - the result is a corrupted element |
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47 | in X, and no error is raised. |
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48 | |
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49 | The private function isoquaternion has been modified to work |
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50 | correctly when the supplied complex number has zero imaginary |
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51 | part. This fixes a problem where log(quaternion(1,0,0,0)) |
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52 | failed instead of returning 0. |
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53 | |
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54 | A number of minor bug fixes have been incorporated. |
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55 | |
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56 | Version 0.8 24 March 2006 |
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57 | |
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58 | With this release we have made available the det, svd and eig |
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59 | functions. There are some limitations in these functions (see |
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60 | the source code) which may be removed in later releases. |
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61 | |
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62 | All of the Fourier transform functions now work for complex |
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63 | quaternions as well as real quaternions. A transform with |
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64 | real data and a real axis will be computed using a quaternion |
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65 | transform. If the data and/or axis is complex, a complex |
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66 | quaternion transform will be computed. |
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67 | |
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68 | The following functions which were previously unimplemented |
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69 | are now implemented and work for real and complex quaternions: |
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70 | log, sin, cos, tan, sinh, cosh, tanh. |
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71 | |
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72 | The function power.m has been implemented, making it possible |
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73 | to raise a quaternion to a power using the .^ notation. This |
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74 | function uses logarithms in the general case, but implements |
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75 | certain special cases such as powers of -1, 0, 1, 2, and 0.5 |
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76 | using more direct calculation. The square root function has |
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77 | also been implemented. |
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78 | |
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79 | The functions isreal and sign have been added. |
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80 | |
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81 | The following functions now work correctly for complex as well |
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82 | as real quaternions: unit, angle, axis, exp, change_basis, |
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83 | orthormal_basis. |
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84 | |
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85 | A directory of test code has been added. There is a script |
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86 | called test.m which runs all the test code, and various |
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87 | scripts for testing parts of the library. The test code is |
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88 | not comprehensive and will be expanded in due course. |
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89 | |
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90 | Structure indexing has been added (in a very limited way). |
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91 | See the function subsref.m for details (work in progress). |
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92 | |
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93 | ------------------------ |
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94 | |
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95 | Version 0.7 27 July 2005 |
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96 | |
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97 | This version is the first released on Sourceforge. |
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