Source code for
vl_demo_kmeans_init.m
This file is located in the toolbox/demo folder in VLFeat package.
% VL_DEMO_KMEANS_INIT
if 0
I = vl_imtest('box') ;
[f, d] = vl_dsift(single(I) / 255, 'step', 1, 'size', 3) ;
X = double(d) ;
numCenters = 300 ;
else
X = [] ;
numCenters = 40 ;
for i=1:numCenters
X_ = randn(10,100) ;
X_(i) = X_(i) + 100 ;
X = [X X_] ;
end
numCenters = numCenters * 2 ;
end
numData = size(X, 2) ;
dimension = size(X, 1) ;
clear elaps energy ;
dimension = 128 ;
numData = 1000 ;
numCenters = 100 ;
numTrials = 5 ;
numIters = 100 ;
vl_twister(0) ;
for trial = 1:numTrials
tic ;
[C, idx, e] = vl_kmeans(X, numCenters, 'Verbose', ...
'Initialization', 'randsel', ...
'MaxNumIterations', numIters) ;
elaps.vlrs(trial) = toc ;
energy.vlrs(trial) = e ;
tic ;
[C_, idx_, e_] = vl_kmeans(X, numCenters, 'Verbose', ...
'Initialization', 'plusplus', ...
'MaxNumIterations', numIters) ;
elaps.vlpp(trial) = toc ;
energy.vlpp(trial) = e_ ;
end
figure(1) ; clf ;
subplot(1,2,1) ; title('Energy') ;
mu = [mean(elaps.vlrs) mean(elaps.vlpp)] ;
st = [std(elaps.vlrs) std(elaps.vlpp)] ;
bar(mu) ; hold on ;
errorbar(mu, st, 'linestyle', 'none', 'color', 'r', 'linewidth', 4) ;
title('Time') ;
subplot(1,2,2) ;
mu = [mean(energy.vlrs) mean(energy.vlpp)] ;
st = [std(energy.vlrs) std(energy.vlpp)] ;
bar(mu) ; hold on ;
errorbar(mu, st, 'linestyle', 'none', 'color', 'r', 'linewidth', 4) ;
title('Energy') ;