inprogress

diff --git a/forester/java/src/org/forester/evoinference/distance/CopyOfNeighborJoiningR.java b/forester/java/src/org/forester/evoinference/distance/CopyOfNeighborJoiningR.java
new file mode 100644 (file)
index 0000000..692287e
--- /dev/null
+++ b/forester/java/src/org/forester/evoinference/distance/CopyOfNeighborJoiningR.java
@@ -0,0 +1,353 @@
+// $Id:
+// FORESTER -- software libraries and applications
+// for evolutionary biology research and applications.
+//
+// Copyright (C) 2014 Christian M. Zmasek
+// All rights reserved
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
+//
+// Contact: phylosoft @ gmail . com
+// WWW: https://sites.google.com/site/cmzmasek/home/software/forester
+
+package org.forester.evoinference.distance;
+
+import java.math.RoundingMode;
+import java.text.DecimalFormat;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map.Entry;
+import java.util.SortedSet;
+
+import org.forester.evoinference.matrix.distance.BasicSymmetricalDistanceMatrix;
+import org.forester.phylogeny.Phylogeny;
+import org.forester.phylogeny.PhylogenyNode;
+import org.forester.util.ForesterUtil;
+
+public final class CopyOfNeighborJoiningR {
+
+    private final static DecimalFormat     DF = new DecimalFormat( "0.00000" );
+    private BasicSymmetricalDistanceMatrix _d;
+    private double[][]                     _d_values;
+    private final DecimalFormat            _df;
+    private PhylogenyNode[]                _external_nodes;
+    private int[]                          _mappings;
+    private int                            _n;
+    private double[]                       _r;
+    private final boolean                  _verbose;
+    private int                            _min_i;
+    private int                            _min_j;
+    private S                              _s;
+    private double                         _d_min;                             //TODO remove me
+
+    private CopyOfNeighborJoiningR() {
+        _verbose = false;
+        _df = null;
+    }
+
+    private CopyOfNeighborJoiningR( final boolean verbose, final int maximum_fraction_digits_for_distances ) {
+        if ( ( maximum_fraction_digits_for_distances < 1 ) || ( maximum_fraction_digits_for_distances > 9 ) ) {
+            throw new IllegalArgumentException( "maximum fraction digits for distances is out of range: "
+                    + maximum_fraction_digits_for_distances );
+        }
+        _verbose = verbose;
+        _df = new DecimalFormat();
+        _df.setMaximumFractionDigits( maximum_fraction_digits_for_distances );
+        _df.setRoundingMode( RoundingMode.HALF_UP );
+    }
+
+    public final Phylogeny execute( final BasicSymmetricalDistanceMatrix distance ) {
+        reset( distance );
+        final Phylogeny phylogeny = new Phylogeny();
+        while ( _n > 2 ) {
+            System.out.println( "N=" + _n );
+            System.out.println();
+            // Calculates the minimal distance.
+            // If more than one minimal distances, always the first found is used
+            final double m = updateM();
+            final int otu1 = _min_i;
+            final int otu2 = _min_j;
+            System.out.println( _min_i + " " + _min_j + " => " + DF.format( m ) + " (" + DF.format( _d_min ) + ")" );
+            // It is a condition that otu1 < otu2.
+            System.out.println( "mapped 1 " + _mappings[ otu1 ] );
+            System.out.println( "mapped 2 " + _mappings[ otu2 ] );
+            final PhylogenyNode node = new PhylogenyNode();
+            final double d = getDvalue( otu1, otu2 );
+            final double d1 = ( d / 2 ) + ( ( _r[ otu1 ] - _r[ otu2 ] ) / ( 2 * ( _n - 2 ) ) );
+            final double d2 = d - d1;
+            if ( _df == null ) {
+                getExternalPhylogenyNode( otu1 ).setDistanceToParent( d1 );
+                getExternalPhylogenyNode( otu2 ).setDistanceToParent( d2 );
+            }
+            else {
+                // yes, yes, slow but only grows with n (and not n^2 or worse)...
+                getExternalPhylogenyNode( otu1 ).setDistanceToParent( Double.parseDouble( _df.format( d1 ) ) );
+                getExternalPhylogenyNode( otu2 ).setDistanceToParent( Double.parseDouble( _df.format( d2 ) ) );
+            }
+            node.addAsChild( getExternalPhylogenyNode( otu1 ) );
+            node.addAsChild( getExternalPhylogenyNode( otu2 ) );
+            if ( _verbose ) {
+                printProgress( otu1, otu2, node );
+                printProgress( _mappings[ otu1 ], _mappings[ otu2 ], node );
+            }
+            System.out.println( "otu1=" + otu1 );
+            System.out.println( "otu2=" + otu2 );
+            calculateDistancesFromNewNode( otu1, otu2, d );
+            _external_nodes[ _mappings[ otu1 ] ] = node;
+            updateMappings( otu2 );
+            --_n;
+            System.out.println( "" );
+            System.out.println( "----------------------------------------------------------------------------------" );
+            System.out.println( "" );
+        }
+        final double d = getDvalue( 0, 1 ) / 2;
+        if ( _df == null ) {
+            getExternalPhylogenyNode( 0 ).setDistanceToParent( d );
+            getExternalPhylogenyNode( 1 ).setDistanceToParent( d );
+        }
+        else {
+            final double dd = Double.parseDouble( _df.format( d ) );
+            getExternalPhylogenyNode( 0 ).setDistanceToParent( dd );
+            getExternalPhylogenyNode( 1 ).setDistanceToParent( dd );
+        }
+        final PhylogenyNode root = new PhylogenyNode();
+        root.addAsChild( getExternalPhylogenyNode( 0 ) );
+        root.addAsChild( getExternalPhylogenyNode( 1 ) );
+        if ( _verbose ) {
+            printProgress( 0, 1, root );
+        }
+        phylogeny.setRoot( root );
+        phylogeny.setRooted( false );
+        return phylogeny;
+    }
+
+    public final List<Phylogeny> execute( final List<BasicSymmetricalDistanceMatrix> distances_list ) {
+        final List<Phylogeny> pl = new ArrayList<Phylogeny>();
+        for( final BasicSymmetricalDistanceMatrix distances : distances_list ) {
+            pl.add( execute( distances ) );
+        }
+        return pl;
+    }
+
+    private final void calculateDistancesFromNewNode( final int otu1, final int otu2, final double d ) {
+        System.out.print( "new D values: " );
+        for( int j = 0; j < _n; ++j ) {
+            if ( ( j == otu1 ) || ( j == otu2 ) ) {
+                continue;
+            }
+            updateDvalue( otu1, otu2, j, d );
+        }
+        System.out.println();
+    }
+
+    private final void updateDvalue( final int otu1, final int otu2, final int j, final double d ) {
+        final double new_d = ( getDvalue( otu1, j ) + getDvalue( j, otu2 ) - d ) / 2;
+        System.out.print( DF.format( new_d ) + " " );
+        System.out.println( "going to remove: " + getDvalue( otu1, j ) + ", " + _mappings[ otu1 ] + ", "
+                + _mappings[ j ] );
+        _s.removePairing( getDvalue( otu1, j ), _mappings[ otu1 ], _mappings[ j ] );
+        System.out.println( "going to remove: " + getDvalue( j, otu2 ) + ", " + _mappings[ otu2 ] + ", "
+                + _mappings[ j ] );
+        _s.removePairing( getDvalue( j, otu2 ), _mappings[ otu2 ], _mappings[ j ] );
+        _s.addPairing( new_d, otu1, _mappings[ j ] );
+        setDvalue( otu1, j, new_d );
+    }
+
+    private void setDvalue( final int i, final int j, final double d ) {
+        if ( i < j ) {
+            _d_values[ _mappings[ i ] ][ _mappings[ j ] ] = d;
+        }
+        _d_values[ _mappings[ j ] ][ _mappings[ i ] ] = d;
+    }
+
+    private double getDvalue( final int i, final int j ) {
+        if ( i < j ) {
+            return _d_values[ _mappings[ i ] ][ _mappings[ j ] ];
+        }
+        return _d_values[ _mappings[ j ] ][ _mappings[ i ] ];
+    }
+
+    private double getDvalueUnmapped( final int i, final int j ) {
+        if ( i < j ) {
+            return _d_values[ i ][ j ];
+        }
+        return _d_values[ j ][ i ];
+    }
+
+    private final void calculateNetDivergences() {
+        for( int i = 0; i < _n; ++i ) {
+            _r[ i ] = calculateNetDivergence( i );
+        }
+    }
+
+    private double calculateNetDivergence( final int i ) {
+        double d = 0;
+        for( int n = 0; n < _n; ++n ) {
+            if ( i != n ) {
+                d += getDvalue( n, i );
+            }
+        }
+        return d;
+    }
+
+    private final PhylogenyNode getExternalPhylogenyNode( final int i ) {
+        return _external_nodes[ _mappings[ i ] ];
+    }
+
+    private final void initExternalNodes() {
+        _external_nodes = new PhylogenyNode[ _n ];
+        String id;
+        for( int i = 0; i < _n; ++i ) {
+            _external_nodes[ i ] = new PhylogenyNode();
+            id = _d.getIdentifier( i );
+            if ( id != null ) {
+                _external_nodes[ i ].setName( id );
+            }
+            else {
+                _external_nodes[ i ].setName( Integer.toString( i ) );
+            }
+            _mappings[ i ] = i;
+        }
+    }
+
+    private final void printProgress( final int otu1, final int otu2, final PhylogenyNode node ) {
+        System.out.println( "Node " + printProgressNodeToString( getExternalPhylogenyNode( otu1 ) ) + " joins "
+                + ( printProgressNodeToString( getExternalPhylogenyNode( otu2 ) ) ) + " [resulting in node "
+                + ( printProgressNodeToString( node ) ) + "]" );
+    }
+
+    private final String printProgressNodeToString( final PhylogenyNode n ) {
+        if ( n.isExternal() ) {
+            if ( ForesterUtil.isEmpty( n.getName() ) ) {
+                return Long.toString( n.getId() );
+            }
+            return n.getName();
+        }
+        return n.getId()
+                + " ("
+                + ( ForesterUtil.isEmpty( n.getChildNode1().getName() ) ? n.getChildNode1().getId() : n.getChildNode1()
+                        .getName() )
+                + "+"
+                + ( ForesterUtil.isEmpty( n.getChildNode2().getName() ) ? n.getChildNode2().getId() : n.getChildNode2()
+                        .getName() ) + ")";
+    }
+
+    // only the values in the lower triangle are used.
+    // !matrix values will be changed!
+    private final void reset( final BasicSymmetricalDistanceMatrix distances ) {
+        _n = distances.getSize();
+        _d = distances;
+        _r = new double[ _n ];
+        _mappings = new int[ _n ];
+        _d_values = _d.getValues();
+        _s = new S();
+        _s.initialize( distances );
+        initExternalNodes();
+        System.out.println();
+        printM();
+        System.out.println( "----------------------------------------------------------------------------------" );
+        System.out.println();
+        System.out.println();
+    }
+
+    final private void printM() {
+        for( int j = 0; j < _d_values.length; ++j ) {
+            System.out.print( _external_nodes[ j ] );
+            System.out.print( "\t\t" );
+            for( int i = 0; i < _d_values[ j ].length; ++i ) {
+                System.out.print( DF.format( _d_values[ i ][ j ] ) );
+                System.out.print( " " );
+            }
+            System.out.println();
+        }
+        for( int j = 0; j < _n; ++j ) {
+            System.out.print( getExternalPhylogenyNode( j ) );
+            System.out.print( "\t\t" );
+            for( int i = 0; i < _n; ++i ) {
+                System.out.print( DF.format( _d_values[ _mappings[ i ] ][ _mappings[ j ] ] ) );
+                System.out.print( " " );
+            }
+            System.out.print( "\t\t" );
+            for( final Entry<Integer, SortedSet<Integer>> entry : _s.getSentrySet( _mappings[ j ] ) ) {
+                System.out.print( DF.format( ( double ) entry.getKey() / S.FACTOR ) + "=" );
+                boolean first = true;
+                for( final int v : entry.getValue() ) {
+                    if ( !first ) {
+                        System.out.print( "," );
+                    }
+                    first = false;
+                    System.out.print( v );
+                }
+                System.out.print( "  " );
+            }
+            System.out.println();
+        }
+    }
+
+    private final double updateM() {
+        calculateNetDivergences();
+        Double min = Double.MAX_VALUE;
+        _min_i = -1;
+        _min_j = -1;
+        final int n_minus_2 = _n - 2;
+        printM();
+        for( int j = 1; j < _n; ++j ) {
+            final double r_j = _r[ j ];
+            final int m_j = _mappings[ j ];
+            for( final Entry<Integer, SortedSet<Integer>> entry : _s.getSentrySet( m_j ) ) {
+                for( final int sorted_i : entry.getValue() ) {
+                    System.out.print( sorted_i + " " );
+                    System.out.print( "(" + DF.format( getDvalueUnmapped( sorted_i, m_j ) ) + ") " );
+                    final double m = getDvalue( sorted_i, j ) - ( ( _r[ sorted_i ] + r_j ) / n_minus_2 );
+                    if ( ( m < min ) && ( sorted_i != j ) ) {
+                        _d_min = getDvalueUnmapped( sorted_i, m_j );
+                        min = m;
+                        _min_i = sorted_i;
+                        _min_j = j;
+                    }
+                }
+            }
+            System.out.println();
+            /*
+            for( int i = 0; i < j; ++i ) {
+                final double m = getDvalue( i, j ) - ( ( _r[ i ] + r_j ) / n_minus_2 );
+                if ( m < min ) {
+                    min = m;
+                    _d_min = getDvalue( i, j );
+                    _min_i = i;
+                    _min_j = j;
+                }
+            }*/
+        }
+        System.out.println();
+        return min;
+    }
+
+    // otu2 will, in effect, be "deleted" from the matrix.
+    private final void updateMappings( final int otu2 ) {
+        for( int i = otu2; i < ( _mappings.length - 1 ); ++i ) {
+            _mappings[ i ] = _mappings[ i + 1 ];
+        }
+    }
+
+    public final static CopyOfNeighborJoiningR createInstance() {
+        return new CopyOfNeighborJoiningR();
+    }
+
+    public final static CopyOfNeighborJoiningR createInstance( final boolean verbose,
+                                                         final int maximum_fraction_digits_for_distances ) {
+        return new CopyOfNeighborJoiningR( verbose, maximum_fraction_digits_for_distances );
+    }
+}

diff --git a/forester/java/src/org/forester/evoinference/distance/NeighborJoiningR.java b/forester/java/src/org/forester/evoinference/distance/NeighborJoiningR.java
index 6ebcbbf..bdc80be 100644 (file)
--- a/forester/java/src/org/forester/evoinference/distance/NeighborJoiningR.java
+++ b/forester/java/src/org/forester/evoinference/distance/NeighborJoiningR.java
@@ -81,20 +81,22 @@ public final class NeighborJoiningR {
             final int otu2 = _min_j;
             System.out.println( _min_i + " " + _min_j + " => " + DF.format( m ) + " (" + DF.format( _d_min ) + ")" );
             // It is a condition that otu1 < otu2.
+            System.out.println( "mapped 1 " + _mappings[ otu1 ] );
+            System.out.println( "mapped 2 " + _mappings[ otu2 ] );
             final PhylogenyNode node = new PhylogenyNode();
-            final double d = getDvalue( otu1, otu2 );
+            final double d = getDvalueUnmapped( otu1, _mappings[ otu2 ] );
             final double d1 = ( d / 2 ) + ( ( _r[ otu1 ] - _r[ otu2 ] ) / ( 2 * ( _n - 2 ) ) );
             final double d2 = d - d1;
             if ( _df == null ) {
-                getExternalPhylogenyNode( otu1 ).setDistanceToParent( d1 );
+                _external_nodes[ otu1 ].setDistanceToParent( d1 );
                 getExternalPhylogenyNode( otu2 ).setDistanceToParent( d2 );
             }
             else {
                 // yes, yes, slow but only grows with n (and not n^2 or worse)...
-                getExternalPhylogenyNode( otu1 ).setDistanceToParent( Double.parseDouble( _df.format( d1 ) ) );
+                _external_nodes[ otu1 ].setDistanceToParent( Double.parseDouble( _df.format( d1 ) ) );
                 getExternalPhylogenyNode( otu2 ).setDistanceToParent( Double.parseDouble( _df.format( d2 ) ) );
             }
-            node.addAsChild( getExternalPhylogenyNode( otu1 ) );
+            node.addAsChild( _external_nodes[ otu1 ] );
             node.addAsChild( getExternalPhylogenyNode( otu2 ) );
             if ( _verbose ) {
                 printProgress( otu1, otu2, node );
@@ -141,30 +143,34 @@ public final class NeighborJoiningR {
     private final void calculateDistancesFromNewNode( final int otu1, final int otu2, final double d ) {
         System.out.print( "new D values: " );
         for( int j = 0; j < _n; ++j ) {
-            if ( ( j == otu1 ) || ( j == otu2 ) ) {
+            if ( j == otu2 ) {
                 continue;
             }
-            updateDvalue( otu1, otu2, j, d );
+            if ( _mappings[ j ] > _mappings[ otu1 ] ) {
+                updateDvalue( otu1, otu2, j, d );
+            }
         }
         System.out.println();
     }
 
     private final void updateDvalue( final int otu1, final int otu2, final int j, final double d ) {
-        final double new_d = ( getDvalue( otu1, j ) + getDvalue( j, otu2 ) - d ) / 2;
+        final double new_d = ( getDvalueUnmapped( otu1, _mappings[ j ] ) + getDvalue( j, otu2 ) - d ) / 2;
         System.out.print( DF.format( new_d ) + " " );
-        System.out.println( "going to remove: " + getDvalue( otu1, j ) + ", " + otu1 + ", " + _mappings[ j ] );
-        _s.removePairing( getDvalue( otu1, j ), _mappings[ otu1 ], _mappings[ j ] );
-        System.out.println( "going to remove: " + getDvalue( j, otu2 ) + ", " + otu2 + ", " + _mappings[ j ] );
+        System.out.println( "going to remove: " + getDvalueUnmapped( otu1, _mappings[ j ] ) + ", " + otu1 + ", "
+                + _mappings[ j ] );
+        _s.removePairing( getDvalueUnmapped( otu1, _mappings[ j ] ), otu1, _mappings[ j ] );
+        System.out.println( "going to remove: " + getDvalue( j, otu2 ) + ", " + _mappings[ otu2 ] + ", "
+                + _mappings[ j ] );
         _s.removePairing( getDvalue( j, otu2 ), _mappings[ otu2 ], _mappings[ j ] );
         _s.addPairing( new_d, otu1, _mappings[ j ] );
-        setDvalue( otu1, j, new_d );
+        setDvalueU( otu1, j, new_d );
     }
 
-    private void setDvalue( final int i, final int j, final double d ) {
-        if ( i < j ) {
-            _d_values[ _mappings[ i ] ][ _mappings[ j ] ] = d;
+    private void setDvalueU( final int i, final int j, final double d ) {
+        if ( i < _mappings[ j ] ) {
+            _d_values[ i ][ _mappings[ j ] ] = d;
         }
-        _d_values[ _mappings[ j ] ][ _mappings[ i ] ] = d;
+        _d_values[ j ][ _mappings[ i ] ] = d;
     }
 
     private double getDvalue( final int i, final int j ) {
@@ -218,7 +224,7 @@ public final class NeighborJoiningR {
     }
 
     private final void printProgress( final int otu1, final int otu2, final PhylogenyNode node ) {
-        System.out.println( "Node " + printProgressNodeToString( getExternalPhylogenyNode( otu1 ) ) + " joins "
+        System.out.println( "Node " + printProgressNodeToString( _external_nodes[ otu1 ] ) + " joins "
                 + ( printProgressNodeToString( getExternalPhylogenyNode( otu2 ) ) ) + " [resulting in node "
                 + ( printProgressNodeToString( node ) ) + "]" );
     }
@@ -258,6 +264,15 @@ public final class NeighborJoiningR {
     }
 
     final private void printM() {
+        for( int j = 0; j < _d_values.length; ++j ) {
+            System.out.print( _external_nodes[ j ] );
+            System.out.print( "\t\t" );
+            for( int i = 0; i < _d_values[ j ].length; ++i ) {
+                System.out.print( DF.format( _d_values[ i ][ j ] ) );
+                System.out.print( " " );
+            }
+            System.out.println();
+        }
         for( int j = 0; j < _n; ++j ) {
             System.out.print( getExternalPhylogenyNode( j ) );
             System.out.print( "\t\t" );
@@ -284,7 +299,7 @@ public final class NeighborJoiningR {
 
     private final double updateM() {
         calculateNetDivergences();
-        Double min = Double.MAX_VALUE;
+        Double min_m = Double.MAX_VALUE;
         _min_i = -1;
         _min_j = -1;
         final int n_minus_2 = _n - 2;
@@ -292,14 +307,15 @@ public final class NeighborJoiningR {
         for( int j = 1; j < _n; ++j ) {
             final double r_j = _r[ j ];
             final int m_j = _mappings[ j ];
+            System.out.print( "j=" + j + "  mj=" + m_j + ":  " );
             for( final Entry<Integer, SortedSet<Integer>> entry : _s.getSentrySet( m_j ) ) {
                 for( final int sorted_i : entry.getValue() ) {
                     System.out.print( sorted_i + " " );
                     System.out.print( "(" + DF.format( getDvalueUnmapped( sorted_i, m_j ) ) + ") " );
-                    final double m = getDvalue( sorted_i, j ) - ( ( _r[ sorted_i ] + r_j ) / n_minus_2 );
-                    if ( ( m < min ) && ( sorted_i != j ) ) {
+                    final double m = getDvalueUnmapped( sorted_i, m_j ) - ( ( _r[ sorted_i ] + r_j ) / n_minus_2 );
+                    if ( ( m < min_m ) && ( sorted_i != j ) ) {
                         _d_min = getDvalueUnmapped( sorted_i, m_j );
-                        min = m;
+                        min_m = m;
                         _min_i = sorted_i;
                         _min_j = j;
                     }
@@ -318,13 +334,18 @@ public final class NeighborJoiningR {
             }*/
         }
         System.out.println();
-        return min;
+        return min_m;
     }
 
     // otu2 will, in effect, be "deleted" from the matrix.
     private final void updateMappings( final int otu2 ) {
         for( int i = otu2; i < ( _mappings.length - 1 ); ++i ) {
+            System.out.print( _mappings[ i ] );
             _mappings[ i ] = _mappings[ i + 1 ];
+            System.out.println( "----->" + _mappings[ i ] );
+        }
+        for( int i = 0; i < _mappings.length; ++i ) {
+            System.out.println( i + "-->" + _mappings[ i ] );
         }
     }
 

diff --git a/forester/java/src/org/forester/evoinference/distance/S.java b/forester/java/src/org/forester/evoinference/distance/S.java
index fe70cd6..f1d94db 100644 (file)
--- a/forester/java/src/org/forester/evoinference/distance/S.java
+++ b/forester/java/src/org/forester/evoinference/distance/S.java
@@ -73,20 +73,20 @@ public final class S {
                 throw new IllegalArgumentException( "key " + key + " (->" + value + ") does not exist for row " + j );
             }
         }
-        if ( x.size() == 1 ) {
-            if ( DEBUG ) {
-                if ( !x.contains( value ) ) {
-                    System.out.println();
-                    System.out
-                            .println( "________________________________________________________________________________________" );
-                    System.out.println( toString() );
-                    throw new IllegalArgumentException( "pairing " + key + "->" + value + " does not exist for row "
-                            + j );
-                }
-            }
-            m.remove( key );
-        }
-        else if ( x.size() > 1 ) {
+        //        if ( x.size() == 1 ) {
+        //            if ( DEBUG ) {
+        //                if ( !x.contains( value ) ) {
+        //                    System.out.println();
+        //                    System.out
+        //                            .println( "________________________________________________________________________________________" );
+        //                    System.out.println( toString() );
+        //                    throw new IllegalArgumentException( "pairing " + key + "->" + value + " does not exist for row "
+        //                            + j );
+        //                }
+        //            }
+        //            m.remove( key );
+        //        }
+        else if ( x.size() >= 1 ) {
             if ( DEBUG ) {
                 if ( !x.remove( value ) ) {
                     throw new IllegalArgumentException( "pairing " + key + "->" + value