mvptree-mediabox

Created: 2012-08-20 23:42
Updated: 2014-01-18 18:44
c

README.md


MVPTree c library version: 1.0.0 date: 2010/12/17 creator: D. Grant Starkweather license: GPLv3 contact: dstarkweather@phash.org, eklinger@phash.org

BACKGROUND:

The MVP tree is a distance-based data structure for the storage and retrieval of n-dimensional datapoints. It relies on the relative distances from selected vantage points to index the points into a tree-like hierarchy. It thus cuts the search space into distinct 'hyper-spheres' around each vantage point.

libmvptree.a is a generic implemention of the mvp tree. It allows the user to define the distance function, the type of data and array length (e.g. its bit width for each data element - 1,2,4 and 8), as well as experiment with various tree shapes (e.g. branch factor, leaf capacity, and a path length variable to save the distances between each point and all all the vantage points).


INSTALLATION:

  1. Type 'make all' to build the libmvptree.a library and test program. Run ./testmvp to do a basic test of the library. More involved tests can be done with ./testmvp2 to test it with various number of randomly simulated data points. Run it without arguments to see what options are available.

    NOTE: For the testing, a specified number of uniformly random datapoints are generated and added to the tree. Then a cluster of datapoints around another randomly chosen point is generated and added to a tree; each element in these data points is a poisson distributed random variable to serve as a difference from the central cluster point's respective element. The point that serves as the center of the cluster is then used to retrieve knearest neighbors

    • in this case, the number in the cluster - from the tree. For the test to be successful, all data points are retrieved.
  2. Type 'make imget' to build the imget program that uses the pHash library. This target requires the pHash library. (www.phash.org) You will need to change CPPFLAGS and PHASH_LIBS variables to reflect the locations of those libraries.

  3. 'make install' to install in the target directory. You might want to edit the Makefile to change the DESTDIR variable from '/usr/local/lib'.

  4. run ./testmvp to run the test program.


API

A demo of the api use exists in the testmvp.c file.


REFERENCES:

Bozkaya, Tolga; Ozsoyoglu, Meral 1999."Indexing Large Metric Spaces for Similarity Search Queries". ACM Transactions in Database Systems, Vol. 24, No. 3, September 1999, pg. 361-404.

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