scikit-learn/examples/svm/plot_svm_iris.py

64 lines
1.6 KiB
Python

#!/usr/bin/python
# -*- coding: utf-8 -*-
"""
=========================================================
SVM-SVC (Support Vector Classification)
=========================================================
The classification application of the SVM is used below. The
`Iris <http://en.wikipedia.org/wiki/Iris_flower_data_set>`_
dataset has been used for this example
The decision boundaries, are shown with all the points in
the training-set.
"""
print __doc__
# Code source: Gael Varoqueux
# Modified for Documentation merge by Jaques Grobler
# License: BSD
import numpy as np
import pylab as pl
from sklearn import svm, datasets
# import some data to play with
iris = datasets.load_iris()
X = iris.data[:, :2] # we only take the first two features.
Y = iris.target
h = .02 # step size in the mesh
clf=svm.SVC(C=20, kernel='linear')
# we create an instance of SVM Classifier and fit the data.
clf.fit(X, Y)
# Plot the decision boundary. For that, we will asign a color to each
# point in the mesh [x_min, m_max]x[y_min, y_max].
x_min, x_max = X[:,0].min() - .5, X[:,0].max() + .5
y_min, y_max = X[:,1].min() - .5, X[:,1].max() + .5
xx, yy = np.meshgrid(np.arange(x_min, x_max, h), np.arange(y_min, y_max, h))
Z = clf.predict(np.c_[xx.ravel(), yy.ravel()])
# Put the result into a color plot
Z = Z.reshape(xx.shape)
pl.figure(1, figsize=(4, 3))
pl.set_cmap(pl.cm.Paired)
pl.pcolormesh(xx, yy, Z)
# Plot also the training points
pl.scatter(X[:,0],X[:,1],c=Y )
pl.xlabel('Sepal length')
pl.ylabel('Sepal width')
pl.xlim(xx.min(), xx.max())
pl.ylim(yy.min(), yy.max())
pl.xticks(())
pl.yticks(())
pl.show()