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Diffstat (limited to 'geom_bottleneck/bottleneck/src/ann/bd_tree.cpp')
| -rw-r--r-- | geom_bottleneck/bottleneck/src/ann/bd_tree.cpp | 422 |
1 files changed, 0 insertions, 422 deletions
diff --git a/geom_bottleneck/bottleneck/src/ann/bd_tree.cpp b/geom_bottleneck/bottleneck/src/ann/bd_tree.cpp deleted file mode 100644 index a5dd69c..0000000 --- a/geom_bottleneck/bottleneck/src/ann/bd_tree.cpp +++ /dev/null @@ -1,422 +0,0 @@ -//---------------------------------------------------------------------- -// File: bd_tree.cpp -// Programmer: David Mount -// Description: Basic methods for bd-trees. -// Last modified: 01/04/05 (Version 1.0) -//---------------------------------------------------------------------- -// Copyright (c) 1997-2005 University of Maryland and Sunil Arya and -// David Mount. All Rights Reserved. -// -// This software and related documentation is part of the Approximate -// Nearest Neighbor Library (ANN). This software is provided under -// the provisions of the Lesser GNU Public License (LGPL). See the -// file ../ReadMe.txt for further information. -// -// The University of Maryland (U.M.) and the authors make no -// representations about the suitability or fitness of this software for -// any purpose. It is provided "as is" without express or implied -// warranty. -//---------------------------------------------------------------------- -// History: -// Revision 0.1 03/04/98 -// Initial release -// Revision l.0 04/01/05 -// Fixed centroid shrink threshold condition to depend on the -// dimension. -// Moved dump routine to kd_dump.cpp. -//---------------------------------------------------------------------- - -#include "bd_tree.h" // bd-tree declarations -#include "kd_util.h" // kd-tree utilities -#include "kd_split.h" // kd-tree splitting rules - -#include <ANN/ANNperf.h> // performance evaluation -#include "def_debug_bt.h" - -namespace geom_bt { -//---------------------------------------------------------------------- -// Printing a bd-tree -// These routines print a bd-tree. See the analogous procedure -// in kd_tree.cpp for more information. -//---------------------------------------------------------------------- - -void ANNbd_shrink::print( // print shrinking node - int level, // depth of node in tree - ostream &out) // output stream -{ -#ifndef FOR_R_TDA - child[ANN_OUT]->print(level+1, out); // print out-child - - out << " "; - for (int i = 0; i < level; i++) // print indentation - out << ".."; - out << "Shrink"; - for (int j = 0; j < n_bnds; j++) { // print sides, 2 per line - if (j % 2 == 0) { - out << "\n"; // newline and indentation - for (int i = 0; i < level+2; i++) out << " "; - } - out << " ([" << bnds[j].cd << "]" - << (bnds[j].sd > 0 ? ">=" : "< ") - << bnds[j].cv << ")"; - } - out << "\n"; - - child[ANN_IN]->print(level+1, out); // print in-child -#endif -} - -//---------------------------------------------------------------------- -// kd_tree statistics utility (for performance evaluation) -// This routine computes various statistics information for -// shrinking nodes. See file kd_tree.cpp for more information. -//---------------------------------------------------------------------- - -void ANNbd_shrink::getStats( // get subtree statistics - int dim, // dimension of space - ANNkdStats &st, // stats (modified) - ANNorthRect &bnd_box) // bounding box -{ - ANNkdStats ch_stats; // stats for children - ANNorthRect inner_box(dim); // inner box of shrink - - annBnds2Box(bnd_box, // enclosing box - dim, // dimension - n_bnds, // number of bounds - bnds, // bounds array - inner_box); // inner box (modified) - // get stats for inner child - ch_stats.reset(); // reset - child[ANN_IN]->getStats(dim, ch_stats, inner_box); - st.merge(ch_stats); // merge them - // get stats for outer child - ch_stats.reset(); // reset - child[ANN_OUT]->getStats(dim, ch_stats, bnd_box); - st.merge(ch_stats); // merge them - - st.depth++; // increment depth - st.n_shr++; // increment number of shrinks -} - -//---------------------------------------------------------------------- -// bd-tree constructor -// This is the main constructor for bd-trees given a set of points. -// It first builds a skeleton kd-tree as a basis, then computes the -// bounding box of the data points, and then invokes rbd_tree() to -// actually build the tree, passing it the appropriate splitting -// and shrinking information. -//---------------------------------------------------------------------- - -ANNkd_ptr rbd_tree( // recursive construction of bd-tree - ANNpointArray pa, // point array - ANNidxArray pidx, // point indices to store in subtree - int n, // number of points - int dim, // dimension of space - int bsp, // bucket space - ANNorthRect &bnd_box, // bounding box for current node - ANNkd_splitter splitter, // splitting routine - ANNshrinkRule shrink); // shrinking rule - -ANNbd_tree::ANNbd_tree( // construct from point array - ANNpointArray pa, // point array (with at least n pts) - int n, // number of points - int dd, // dimension - int bs, // bucket size - ANNsplitRule split, // splitting rule - ANNshrinkRule shrink) // shrinking rule - : ANNkd_tree(n, dd, bs) // build skeleton base tree -{ - pts = pa; // where the points are - if (n == 0) return; // no points--no sweat - - ANNorthRect bnd_box(dd); // bounding box for points - // construct bounding rectangle - annEnclRect(pa, pidx, n, dd, bnd_box); - // copy to tree structure - bnd_box_lo = annCopyPt(dd, bnd_box.lo); - bnd_box_hi = annCopyPt(dd, bnd_box.hi); - - switch (split) { // build by rule - case ANN_KD_STD: // standard kd-splitting rule - root = rbd_tree(pa, pidx, n, dd, bs, bnd_box, kd_split, shrink); - break; - case ANN_KD_MIDPT: // midpoint split - root = rbd_tree(pa, pidx, n, dd, bs, bnd_box, midpt_split, shrink); - break; - case ANN_KD_SUGGEST: // best (in our opinion) - case ANN_KD_SL_MIDPT: // sliding midpoint split - root = rbd_tree(pa, pidx, n, dd, bs, bnd_box, sl_midpt_split, shrink); - break; - case ANN_KD_FAIR: // fair split - root = rbd_tree(pa, pidx, n, dd, bs, bnd_box, fair_split, shrink); - break; - case ANN_KD_SL_FAIR: // sliding fair split - root = rbd_tree(pa, pidx, n, dd, bs, - bnd_box, sl_fair_split, shrink); - break; - default: - annError("Illegal splitting method", ANNabort); - } -} - -//---------------------------------------------------------------------- -// Shrinking rules -//---------------------------------------------------------------------- - -enum ANNdecomp {SPLIT, SHRINK}; // decomposition methods - -//---------------------------------------------------------------------- -// trySimpleShrink - Attempt a simple shrink -// -// We compute the tight bounding box of the points, and compute -// the 2*dim ``gaps'' between the sides of the tight box and the -// bounding box. If any of the gaps is large enough relative to -// the longest side of the tight bounding box, then we shrink -// all sides whose gaps are large enough. (The reason for -// comparing against the tight bounding box, is that after -// shrinking the longest box size will decrease, and if we use -// the standard bounding box, we may decide to shrink twice in -// a row. Since the tight box is fixed, we cannot shrink twice -// consecutively.) -//---------------------------------------------------------------------- -const float BD_GAP_THRESH = 0.5; // gap threshold (must be < 1) -const int BD_CT_THRESH = 2; // min number of shrink sides - -ANNdecomp trySimpleShrink( // try a simple shrink - ANNpointArray pa, // point array - ANNidxArray pidx, // point indices to store in subtree - int n, // number of points - int dim, // dimension of space - const ANNorthRect &bnd_box, // current bounding box - ANNorthRect &inner_box) // inner box if shrinking (returned) -{ - int i; - // compute tight bounding box - annEnclRect(pa, pidx, n, dim, inner_box); - - ANNcoord max_length = 0; // find longest box side - for (i = 0; i < dim; i++) { - ANNcoord length = inner_box.hi[i] - inner_box.lo[i]; - if (length > max_length) { - max_length = length; - } - } - - int shrink_ct = 0; // number of sides we shrunk - for (i = 0; i < dim; i++) { // select which sides to shrink - // gap between boxes - ANNcoord gap_hi = bnd_box.hi[i] - inner_box.hi[i]; - // big enough gap to shrink? - if (gap_hi < max_length*BD_GAP_THRESH) - inner_box.hi[i] = bnd_box.hi[i]; // no - expand - else shrink_ct++; // yes - shrink this side - - // repeat for high side - ANNcoord gap_lo = inner_box.lo[i] - bnd_box.lo[i]; - if (gap_lo < max_length*BD_GAP_THRESH) - inner_box.lo[i] = bnd_box.lo[i]; // no - expand - else shrink_ct++; // yes - shrink this side - } - - if (shrink_ct >= BD_CT_THRESH) // did we shrink enough sides? - return SHRINK; - else return SPLIT; -} - -//---------------------------------------------------------------------- -// tryCentroidShrink - Attempt a centroid shrink -// -// We repeatedly apply the splitting rule, always to the larger subset -// of points, until the number of points decreases by the constant -// fraction BD_FRACTION. If this takes more than dim*BD_MAX_SPLIT_FAC -// splits for this to happen, then we shrink to the final inner box -// Otherwise we split. -//---------------------------------------------------------------------- - -const float BD_MAX_SPLIT_FAC = 0.5; // maximum number of splits allowed -const float BD_FRACTION = 0.5; // ...to reduce points by this fraction - // ...This must be < 1. - -ANNdecomp tryCentroidShrink( // try a centroid shrink - ANNpointArray pa, // point array - ANNidxArray pidx, // point indices to store in subtree - int n, // number of points - int dim, // dimension of space - const ANNorthRect &bnd_box, // current bounding box - ANNkd_splitter splitter, // splitting procedure - ANNorthRect &inner_box) // inner box if shrinking (returned) -{ - int n_sub = n; // number of points in subset - int n_goal = (int) (n*BD_FRACTION); // number of point in goal - int n_splits = 0; // number of splits needed - // initialize inner box to bounding box - annAssignRect(dim, inner_box, bnd_box); - - while (n_sub > n_goal) { // keep splitting until goal reached - int cd; // cut dim from splitter (ignored) - ANNcoord cv; // cut value from splitter (ignored) - int n_lo; // number of points on low side - // invoke splitting procedure - (*splitter)(pa, pidx, inner_box, n_sub, dim, cd, cv, n_lo); - n_splits++; // increment split count - - if (n_lo >= n_sub/2) { // most points on low side - inner_box.hi[cd] = cv; // collapse high side - n_sub = n_lo; // recurse on lower points - } - else { // most points on high side - inner_box.lo[cd] = cv; // collapse low side - pidx += n_lo; // recurse on higher points - n_sub -= n_lo; - } - } - if (n_splits > dim*BD_MAX_SPLIT_FAC)// took too many splits - return SHRINK; // shrink to final subset - else - return SPLIT; -} - -//---------------------------------------------------------------------- -// selectDecomp - select which decomposition to use -//---------------------------------------------------------------------- - -ANNdecomp selectDecomp( // select decomposition method - ANNpointArray pa, // point array - ANNidxArray pidx, // point indices to store in subtree - int n, // number of points - int dim, // dimension of space - const ANNorthRect &bnd_box, // current bounding box - ANNkd_splitter splitter, // splitting procedure - ANNshrinkRule shrink, // shrinking rule - ANNorthRect &inner_box) // inner box if shrinking (returned) -{ - ANNdecomp decomp = SPLIT; // decomposition - - switch (shrink) { // check shrinking rule - case ANN_BD_NONE: // no shrinking allowed - decomp = SPLIT; - break; - case ANN_BD_SUGGEST: // author's suggestion - case ANN_BD_SIMPLE: // simple shrink - decomp = trySimpleShrink( - pa, pidx, // points and indices - n, dim, // number of points and dimension - bnd_box, // current bounding box - inner_box); // inner box if shrinking (returned) - break; - case ANN_BD_CENTROID: // centroid shrink - decomp = tryCentroidShrink( - pa, pidx, // points and indices - n, dim, // number of points and dimension - bnd_box, // current bounding box - splitter, // splitting procedure - inner_box); // inner box if shrinking (returned) - break; - default: - annError("Illegal shrinking rule", ANNabort); - } - return decomp; -} - -//---------------------------------------------------------------------- -// rbd_tree - recursive procedure to build a bd-tree -// -// This is analogous to rkd_tree, but for bd-trees. See the -// procedure rkd_tree() in kd_split.cpp for more information. -// -// If the number of points falls below the bucket size, then a -// leaf node is created for the points. Otherwise we invoke the -// procedure selectDecomp() which determines whether we are to -// split or shrink. If splitting is chosen, then we essentially -// do exactly as rkd_tree() would, and invoke the specified -// splitting procedure to the points. Otherwise, the selection -// procedure returns a bounding box, from which we extract the -// appropriate shrinking bounds, and create a shrinking node. -// Finally the points are subdivided, and the procedure is -// invoked recursively on the two subsets to form the children. -//---------------------------------------------------------------------- - -ANNkd_ptr rbd_tree( // recursive construction of bd-tree - ANNpointArray pa, // point array - ANNidxArray pidx, // point indices to store in subtree - int n, // number of points - int dim, // dimension of space - int bsp, // bucket space - ANNorthRect &bnd_box, // bounding box for current node - ANNkd_splitter splitter, // splitting routine - ANNshrinkRule shrink) // shrinking rule -{ - ANNdecomp decomp; // decomposition method - - ANNorthRect inner_box(dim); // inner box (if shrinking) - - if (n <= bsp) { // n small, make a leaf node - if (n == 0) // empty leaf node - return KD_TRIVIAL; // return (canonical) empty leaf - else // construct the node and return - return new ANNkd_leaf(n, pidx); - } - - decomp = selectDecomp( // select decomposition method - pa, pidx, // points and indices - n, dim, // number of points and dimension - bnd_box, // current bounding box - splitter, shrink, // splitting/shrinking methods - inner_box); // inner box if shrinking (returned) - - if (decomp == SPLIT) { // split selected - int cd; // cutting dimension - ANNcoord cv; // cutting value - int n_lo; // number on low side of cut - // invoke splitting procedure - (*splitter)(pa, pidx, bnd_box, n, dim, cd, cv, n_lo); - - ANNcoord lv = bnd_box.lo[cd]; // save bounds for cutting dimension - ANNcoord hv = bnd_box.hi[cd]; - - bnd_box.hi[cd] = cv; // modify bounds for left subtree - ANNkd_ptr lo = rbd_tree( // build left subtree - pa, pidx, n_lo, // ...from pidx[0..n_lo-1] - dim, bsp, bnd_box, splitter, shrink); - bnd_box.hi[cd] = hv; // restore bounds - - bnd_box.lo[cd] = cv; // modify bounds for right subtree - ANNkd_ptr hi = rbd_tree( // build right subtree - pa, pidx + n_lo, n-n_lo,// ...from pidx[n_lo..n-1] - dim, bsp, bnd_box, splitter, shrink); - bnd_box.lo[cd] = lv; // restore bounds - // create the splitting node - return new ANNkd_split(cd, cv, lv, hv, lo, hi); - } - else { // shrink selected - int n_in; // number of points in box - int n_bnds; // number of bounding sides - - annBoxSplit( // split points around inner box - pa, // points to split - pidx, // point indices - n, // number of points - dim, // dimension - inner_box, // inner box - n_in); // number of points inside (returned) - - ANNkd_ptr in = rbd_tree( // build inner subtree pidx[0..n_in-1] - pa, pidx, n_in, dim, bsp, inner_box, splitter, shrink); - ANNkd_ptr out = rbd_tree( // build outer subtree pidx[n_in..n] - pa, pidx+n_in, n - n_in, dim, bsp, bnd_box, splitter, shrink); - - ANNorthHSArray bnds = NULL; // bounds (alloc in Box2Bnds and - // ...freed in bd_shrink destroyer) - - annBox2Bnds( // convert inner box to bounds - inner_box, // inner box - bnd_box, // enclosing box - dim, // dimension - n_bnds, // number of bounds (returned) - bnds); // bounds array (modified) - - // return shrinking node - return new ANNbd_shrink(n_bnds, bnds, in, out); - } -} -} |