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kNN – Model Flexibility in Pictures

TODO

import numpy as np

import mvpa2
from mvpa2.base import cfg
from mvpa2.misc.data_generators import *
from mvpa2.clfs.knn import kNN
from mvpa2.misc.plot import *

mvpa2.seed(0)                            # to reproduce the plot

dataset_kwargs = dict(nfeatures=2, nchunks=10,
    snr=2, nlabels=4, means=[ [0,1], [1,0], [1,1], [0,0] ])

dataset_train = normal_feature_dataset(**dataset_kwargs)
dataset_plot = normal_feature_dataset(**dataset_kwargs)


# make a new figure
pl.figure(figsize=(9, 9))

for i,k in enumerate((1, 3, 9, 20)):
    knn = kNN(k)

    print "Processing kNN(%i) problem..." % k
    pl.subplot(2, 2, i+1)

»    knn.train(dataset_train)

     plot_decision_boundary_2d(
         dataset_plot, clf=knn, maps='targets')

See also

The full source code of this example is included in the PyMVPA source distribution (doc/examples/knn_plot.py).