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"""
To run this, you'll need to have installed.
* glmnet-python
* scikit-learn (of course)
Does two benchmarks
First, we fix a training set and increase the number of
samples. Then we plot the computation time as function of
the number of samples.
In the second benchmark, we increase the number of dimensions of the
training set. Then we plot the computation time as function of
the number of dimensions.
In both cases, only 10% of the features are informative.
"""
import numpy as np
import gc
from time import time
from sklearn.datasets.samples_generator import make_regression
alpha = 0.1
# alpha = 0.01
def rmse(a, b):
return np.sqrt(np.mean((a - b) ** 2))
def bench(factory, X, Y, X_test, Y_test, ref_coef):
gc.collect()
# start time
tstart = time()
clf = factory(alpha=alpha).fit(X, Y)
delta = (time() - tstart)
# stop time
print "duration: %0.3fs" % delta
print "rmse: %f" % rmse(Y_test, clf.predict(X_test))
print "mean coef abs diff: %f" % abs(ref_coef - clf.coef_.ravel()).mean()
return delta
if __name__ == '__main__':
from glmnet.elastic_net import Lasso as GlmnetLasso
from sklearn.linear_model import Lasso as ScikitLasso
# Delayed import of pylab
import pylab as pl
scikit_results = []
glmnet_results = []
n = 20
step = 500
n_features = 1000
n_informative = n_features / 10
n_test_samples = 1000
for i in range(1, n + 1):
print '=================='
print 'Iteration %s of %s' % (i, n)
print '=================='
X, Y, coef_ = make_regression(
n_samples=(i * step) + n_test_samples, n_features=n_features,
noise=0.1, n_informative=n_informative, coef=True)
X_test = X[-n_test_samples:]
Y_test = Y[-n_test_samples:]
X = X[:(i * step)]
Y = Y[:(i * step)]
print "benching scikit: "
scikit_results.append(bench(ScikitLasso, X, Y, X_test, Y_test, coef_))
print "benching glmnet: "
glmnet_results.append(bench(GlmnetLasso, X, Y, X_test, Y_test, coef_))
pl.clf()
xx = range(0, n * step, step)
pl.title('Lasso regression on sample dataset (%d features)' % n_features)
pl.plot(xx, scikit_results, 'b-', label='scikit-learn')
pl.plot(xx, glmnet_results, 'r-', label='glmnet')
pl.legend()
pl.xlabel('number of samples to classify')
pl.ylabel('time (in seconds)')
pl.show()
# now do a bench where the number of points is fixed
# and the variable is the number of features
scikit_results = []
glmnet_results = []
n = 20
step = 100
n_samples = 500
for i in range(1, n + 1):
print '=================='
print 'Iteration %02d of %02d' % (i, n)
print '=================='
n_features = i * step
n_informative = n_features / 10
X, Y, coef_ = make_regression(
n_samples=(i * step) + n_test_samples, n_features=n_features,
noise=0.1, n_informative=n_informative, coef=True)
X_test = X[-n_test_samples:]
Y_test = Y[-n_test_samples:]
X = X[:n_samples]
Y = Y[:n_samples]
print "benching scikit: "
scikit_results.append(bench(ScikitLasso, X, Y, X_test, Y_test, coef_))
print "benching glmnet: "
glmnet_results.append(bench(GlmnetLasso, X, Y, X_test, Y_test, coef_))
xx = np.arange(100, 100 + n * step, step)
pl.figure()
pl.title('Regression in high dimensional spaces (%d samples)' % n_samples)
pl.plot(xx, scikit_results, 'b-', label='scikit-learn')
pl.plot(xx, glmnet_results, 'r-', label='glmnet')
pl.legend()
pl.xlabel('number of features')
pl.ylabel('time (in seconds)')
pl.axis('tight')
pl.show()
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