# HG changeset patch
# User mas01mc
# Date 1233028159 0
# Node ID 237d5a03d31796eff010577895b80414d7ed07e4
# Parent  0767731a6ccecb7eb6b60704234a34b51fde6190
Working version of multiprobe LSH. Passes tests. But needs testing vis-a-vis TP improvement. In the process, found a bug in hash function projections on rare occasions admitting negative values. This only shows for large datasets and was fatal for multiprobe.

diff -r 0767731a6cce -r 237d5a03d317 Makefile
--- a/Makefile	Mon Jan 26 13:19:09 2009 +0000
+++ b/Makefile	Tue Jan 27 03:49:19 2009 +0000
@@ -17,7 +17,7 @@
 MINORVERSION=0
 LIBRARY=lib$(EXECUTABLE).so.$(SOVERSION).$(MINORVERSION)
 
-override CFLAGS+=-g -ggdb -fPIC
+override CFLAGS+=-O3 -g -fPIC
 
 # set to DUMP hashtables on QUERY load
 #override CFLAGS+=-DLSH_DUMP_CORE_TABLES
diff -r 0767731a6cce -r 237d5a03d317 lshlib.cpp
--- a/lshlib.cpp	Mon Jan 26 13:19:09 2009 +0000
+++ b/lshlib.cpp	Tue Jan 27 03:49:19 2009 +0000
@@ -324,7 +324,10 @@
 	tmp += *pA++ * *vi++;  // project
       tmp += *pb;              // translate
       tmp *= iw;               // scale
-      *pg = (Uns32T) (floor(tmp));      // hash function g_j(v)=[x1 x2 ... xk]; xk \in Z
+      tmp = floor(tmp);        // handle negative values
+      while(tmp<0)             // wrap around 0 to N
+	tmp += H::N;
+      *pg = (Uns32T) tmp;      // hash function g_j(v)=[x1 x2 ... xk]; xk \in Z
       *bd = (tmp - *pg++);//*w;       // boundary distance -1
       *(bd+1) = (1.0f - *bd); //*w;    // boundary distance +1
       bd+=2;