This commit is contained in:
Morten Hjorth-Jensen
2024-09-10 06:14:12 +02:00
parent 6cd669aa24
commit 6ab196695f
7 changed files with 812 additions and 804 deletions
+7 -10
View File
@@ -1102,11 +1102,6 @@ You may also find this recent "article":"https://www.pnas.org/content/116/32/158
!split
===== Another Example from Scikit-Learn's Repository =====
!bc pycod
"""
============================
Underfitting vs. Overfitting
============================
This example demonstrates the problems of underfitting and overfitting and
how we can use linear regression with polynomial features to approximate
@@ -1115,17 +1110,19 @@ which is a part of the cosine function. In addition, the samples from the
real function and the approximations of different models are displayed. The
models have polynomial features of different degrees. We can see that a
linear function (polynomial with degree 1) is not sufficient to fit the
training samples. This is called **underfitting**. A polynomial of degree 4
training samples. This is called _underfitting_. A polynomial of degree 4
approximates the true function almost perfectly. However, for higher degrees
the model will **overfit** the training data, i.e. it learns the noise of the
the model will _overfit_ the training data, i.e. it learns the noise of the
training data.
We evaluate quantitatively **overfitting** / **underfitting** by using
We evaluate quantitatively overfitting and underfitting by using
cross-validation. We calculate the mean squared error (MSE) on the validation
set, the higher, the less likely the model generalizes correctly from the
training data.
"""
print(__doc__)
!bc pycod
#print(__doc__)
import numpy as np
import matplotlib.pyplot as plt