dlib/python_examples/svm_binary_classifier.py

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2017-10-18 19:36:31 +08:00
#!/usr/bin/python
# The contents of this file are in the public domain. See LICENSE_FOR_EXAMPLE_PROGRAMS.txt
#
#
# This is an example illustrating the use of a binary SVM classifier tool from
# the dlib C++ Library. In this example, we will create a simple test dataset
# and show how to learn a classifier from it.
#
#
# COMPILING/INSTALLING THE DLIB PYTHON INTERFACE
# You can install dlib using the command:
# pip install dlib
#
# Alternatively, if you want to compile dlib yourself then go into the dlib
# root folder and run:
# python setup.py install
# or
# python setup.py install --yes USE_AVX_INSTRUCTIONS
# if you have a CPU that supports AVX instructions, since this makes some
# things run faster.
#
# Compiling dlib should work on any operating system so long as you have
# CMake and boost-python installed. On Ubuntu, this can be done easily by
# running the command:
# sudo apt-get install libboost-python-dev cmake
#
import dlib
import pickle
x = dlib.vectors()
y = dlib.array()
# Make a training dataset. Here we have just two training examples. Normally
# you would use a much larger training dataset, but for the purpose of example
# this is plenty. For binary classification, the y labels should all be either +1 or -1.
x.append(dlib.vector([1, 2, 3, -1, -2, -3]))
y.append(+1)
x.append(dlib.vector([-1, -2, -3, 1, 2, 3]))
y.append(-1)
# Now make a training object. This object is responsible for turning a
# training dataset into a prediction model. This one here is a SVM trainer
# that uses a linear kernel. If you wanted to use a RBF kernel or histogram
# intersection kernel you could change it to one of these lines:
# svm = dlib.svm_c_trainer_histogram_intersection()
# svm = dlib.svm_c_trainer_radial_basis()
svm = dlib.svm_c_trainer_linear()
svm.be_verbose = True
svm.set_c(10)
# Now train the model. The return value is the trained model capable of making predictions.
classifier = svm.train(x, y)
# Now run the model on our data and look at the results.
print("prediction for first sample: {}".format(classifier(x[0])))
print("prediction for second sample: {}".format(classifier(x[1])))
# classifier models can also be pickled in the same was as any other python object.
with open('saved_model.pickle', 'wb') as handle:
pickle.dump(classifier, handle)