plots.py
No OneTemporary
Actions

Subscribers

None

File Metadata

	# -- coding: utf-8 --
	"""a function of ploting figures."""
	import numpy as np
	from build_polynomial import *
	import matplotlib.pyplot as plt


	def plot_fitted_curve(y, x, weights, degree, ax):
	"""plot the fitted curve."""
	ax.scatter(x, y, color='b', s=12, facecolors='none', edgecolors='r')
	xvals = np.arange(min(x) - 0.1, max(x) + 0.1, 0.1)
	tx = build_poly(xvals, degree)
	f = tx.dot(weights)
	ax.plot(xvals, f)
	ax.set_xlabel("x")
	ax.set_ylabel("y")
	ax.set_title("Polynomial degree " + str(degree))

	def plot_train_test(train_errors, test_errors, lambdas, degree):
	"""
	train_errors, test_errors and lambas should be list (of the same size) the respective train error and test error for a given lambda,
	* lambda[0] = 1
	* train_errors[0] = RMSE of a ridge regression on the train set
	* test_errors[0] = RMSE of the parameter found by ridge regression applied on the test set

	degree is just used for the title of the plot.
	"""
	plt.semilogx(lambdas, train_errors, color='b', marker='*', label="Train error")
	plt.semilogx(lambdas, test_errors, color='r', marker='*', label="Test error")
	plt.xlabel("lambda")
	plt.ylabel("RMSE")
	plt.title("Ridge regression for polynomial degree " + str(degree))
	leg = plt.legend(loc=1, shadow=True)
	leg.draw_frame(False)
	plt.savefig("ridge_regression")