Mercurial > hg > audiodb
changeset 521:237d5a03d317 multiprobeLSH
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.
| author | mas01mc |
|---|---|
| date | Tue, 27 Jan 2009 03:49:19 +0000 |
| parents | 0767731a6cce |
| children | dad3d252462a |
| files | Makefile lshlib.cpp |
| diffstat | 2 files changed, 5 insertions(+), 2 deletions(-) [+] |
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--- 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
--- 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;