| 1 | #Please insert up references in the next lines (line starts with keyword UP) |
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| 2 | UP arb.hlp |
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| 3 | UP glossary.hlp |
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| 4 | UP pars.hlp |
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| 5 | UP mode_nni.hlp |
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| 6 | UP mode_optimize.hlp |
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| 7 | |
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| 8 | #Please insert subtopic references (line starts with keyword SUB) |
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| 9 | #SUB subtopic.hlp |
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| 10 | |
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| 11 | # Hypertext links in helptext can be added like this: LINK{ref.hlp|http://add|bla@domain} |
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| 12 | |
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| 13 | #************* Title of helpfile !! and start of real helpfile ******** |
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| 14 | TITLE K.L. optimization |
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| 15 | |
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| 16 | OCCURRENCE ARB_PARSIMONY/<K.L.-mode-button> |
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| 17 | as part of LINK{pa_globopti.hlp} |
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| 18 | |
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| 19 | DESCRIPTION Searches for a better (more parsimonious) tree by swapping |
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| 20 | subtrees which are separated by many edges. |
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| 21 | |
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| 22 | Not all possible topologies are tested here, because there |
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| 23 | are far too many (see LINK{kernlin.hlp} for details). |
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| 24 | |
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| 25 | Instead the K.L. optimizer selects several "paths" through the tree (we call |
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| 26 | this selection 'path reduction') and follows only those paths, while performing |
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| 27 | NNIs (see LINK{nni.hlp}) along it's way. |
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| 28 | |
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| 29 | These NNIs are even attempted, when single NNIs degrade the quality of the topology. |
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| 30 | If some intermediate or the final NNI (which is by default done 15 edges away from |
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| 31 | the edge starting from) leads to an improvement of the tree, the topology change |
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| 32 | is kept. Otherwise all changes are undone and the next path will be attempted. |
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| 33 | |
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| 34 | The default maximum path length of 15 and several parameters concerning the path reduction |
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| 35 | may be configured in LINK{kernlin.hlp}. |
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| 36 | |
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| 37 | NOTES The K.L. optimization occurs as step 2 of LINK{pa_globopti.hlp}. |
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| 38 | |
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| 39 | It can be called directly using LINK{mode_kernlin.hlp}. |
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| 40 | |
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| 41 | EXAMPLES None |
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| 42 | |
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| 43 | WARNINGS None |
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| 44 | |
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| 45 | BUGS No bugs known |
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