update on cnn
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@@ -272,7 +272,7 @@ The scikit-learn dataset we will use consists of a selection of 1797 images of s
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<p>
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To feed data into a feed-forward neural network we need to represent
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the inputs as a feature matrix \( X = (n_{inputs}, n_{features}) \). Each
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the inputs as a design/feature matrix \( X = (n_{inputs}, n_{features}) \). Each
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row represents an <em>input</em>, in this case a handwritten digit, and
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each column represents a <em>feature</em>, in this case a pixel. The
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correct answers, also known as <em>labels</em> or <em>targets</em> are
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@@ -282,7 +282,7 @@ represented as a 1D array of integers
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<p>
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As an example, say we want to build a neural network using supervised learning to predict Body-Mass Index (BMI) from
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measurements of height (in m)
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and weight (in kg). If we have measurements of 5 people the feature matrix could be for example:
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and weight (in kg). If we have measurements of 5 people the design/feature matrix could be for example:
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$$ X = \begin{bmatrix}
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1.85 & 81\\
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@@ -300,7 +300,7 @@ $$ Y = (23.7, 22.2, 27.1, 17.5, 21.1) $$
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<p>
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Since each input image is a 2D matrix, we need to flatten the image
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(i.e. "unravel" the 2D matrix into a 1D array) to turn the data into a
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feature matrix. This means we lose all spatial information in the
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design/feature matrix. This means we lose all spatial information in the
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image, such as locality and translational invariance. More complicated
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architectures such as Convolutional Neural Networks can take advantage
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of such information, and are most commonly applied when analyzing
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