update
This commit is contained in:
@@ -644,7 +644,7 @@ role when we develop a specific machine learning algorithm.</p>
|
||||
<p>Machine learning is an extremely rich field, in spite of its young
|
||||
age. The increases we have seen during the last three decades in
|
||||
computational capabilities have been followed by developments of
|
||||
methods and techniques for analyzing and handling large date sets,
|
||||
methods and techniques for analyzing and handling large data sets,
|
||||
relying heavily on statistics, computer science and mathematics. The
|
||||
field is rather new and developing rapidly. Popular software packages
|
||||
written in Python for machine learning like
|
||||
@@ -666,7 +666,7 @@ two main categories. In <em>supervised learning</em> we know the answer to a
|
||||
problem, and let the computer deduce the logic behind it. On the other
|
||||
hand, <em>unsupervised learning</em> is a method for finding patterns and
|
||||
relationship in data sets without any prior knowledge of the system.
|
||||
Some authours also operate with a third category, namely
|
||||
Some authors also operate with a third category, namely
|
||||
<em>reinforcement learning</em>. This is a paradigm of learning inspired by
|
||||
behavioral psychology, where learning is achieved by trial-and-error,
|
||||
solely from rewards and punishment.</p>
|
||||
@@ -714,13 +714,13 @@ what is the likelihood of finding <span class="math notranslate nohighlight">\(B
|
||||
<h3><span class="section-number">3.2.2. </span>What is a good model?<a class="headerlink" href="#what-is-a-good-model" title="Permalink to this headline">¶</a></h3>
|
||||
<p>In science and engineering we often end up in situations where we want to infer (or learn) a
|
||||
quantitative model <span class="math notranslate nohighlight">\(M\)</span> for a given set of sample points <span class="math notranslate nohighlight">\(\boldsymbol{X} \in [x_1, x_2,\dots x_N]\)</span>.</p>
|
||||
<p>As we will see repeatedely in these lectures, we could try to fit these data points to a model given by a
|
||||
<p>As we will see repeatedly in these lectures, we could try to fit these data points to a model given by a
|
||||
straight line, or if we wish to be more sophisticated to a more complex
|
||||
function.</p>
|
||||
<p>The reason for inferring such a model is that it
|
||||
serves many useful purposes. On the one hand, the model can reveal information
|
||||
encoded in the data or underlying mechanisms from which the data were generated. For instance, we could discover important
|
||||
corelations that relate interesting physics interpretations.</p>
|
||||
correlations that relate interesting physics interpretations.</p>
|
||||
<p>In addition, it can simplify the representation of the given data set and help
|
||||
us in making predictions about future data samples.</p>
|
||||
<p>A first important consideration to keep in mind is that inferring the <em>correct</em> model
|
||||
@@ -843,7 +843,7 @@ y = 10x+0.01 \times N(0,1),
|
||||
<p>where <span class="math notranslate nohighlight">\(x\)</span> is defined as before. Does the fit look better? Indeed, by
|
||||
reducing the role of the noise given by the normal distribution we see immediately that
|
||||
our linear prediction seemingly reproduces better the training
|
||||
set. However, this testing ‘by the eye’ is obviouly not satisfactory in the
|
||||
set. However, this testing ‘by the eye’ is obviously not satisfactory in the
|
||||
long run. Here we have only defined the training data and our model, and
|
||||
have not discussed a more rigorous approach to the <strong>cost</strong> function.</p>
|
||||
<p>We need more rigorous criteria in defining whether we have succeeded or
|
||||
@@ -957,13 +957,13 @@ example of the functionality of <strong>Scikit-Learn</strong>.</p>
|
||||
</div>
|
||||
<div class="cell_output docutils container">
|
||||
<div class="output stream highlight-myst-ansi notranslate"><div class="highlight"><pre><span></span>The intercept alpha:
|
||||
[2.02408959]
|
||||
[2.03523311]
|
||||
Coefficient beta :
|
||||
[[4.92811987]]
|
||||
Mean squared error: 0.25
|
||||
Variance score: 0.89
|
||||
[[4.99498108]]
|
||||
Mean squared error: 0.27
|
||||
Variance score: 0.87
|
||||
Mean squared log error: 0.01
|
||||
Mean absolute error: 0.39
|
||||
Mean absolute error: 0.41
|
||||
</pre></div>
|
||||
</div>
|
||||
<img alt="_images/chapter1_19_1.png" src="_images/chapter1_19_1.png" />
|
||||
@@ -1063,7 +1063,7 @@ a linear <span class="math notranslate nohighlight">\(x\)</span>-dependence we s
|
||||
</div>
|
||||
<div class="cell_output docutils container">
|
||||
<img alt="_images/chapter1_33_0.png" src="_images/chapter1_33_0.png" />
|
||||
<div class="output stream highlight-myst-ansi notranslate"><div class="highlight"><pre><span></span>0.005
|
||||
<div class="output stream highlight-myst-ansi notranslate"><div class="highlight"><pre><span></span>0.00499999999999999
|
||||
</pre></div>
|
||||
</div>
|
||||
</div>
|
||||
|
||||
Reference in New Issue
Block a user