Exercise:Self-Taught Learning

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(Step Five: Classifying on the test set)
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''If you have not completed the exercises listed above, we strongly suggest you complete them first.''
''If you have not completed the exercises listed above, we strongly suggest you complete them first.''
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===Step One: Generate the input and test data sets===
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===Step 1: Generate the input and test data sets===
Download and decompress <tt>[http://ufldl.stanford.edu/wiki/resources/stl_exercise.zip stl_exercise.zip]</tt>, which contains starter code for this exercise. Additionally, you will need to download the datasets from the MNIST Handwritten Digit Database for this project.
Download and decompress <tt>[http://ufldl.stanford.edu/wiki/resources/stl_exercise.zip stl_exercise.zip]</tt>, which contains starter code for this exercise. Additionally, you will need to download the datasets from the MNIST Handwritten Digit Database for this project.
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===Step Two: Train the sparse autoencoder===
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===Step 2: Train the sparse autoencoder===
Next, we will train the unlabeled dataset on the sparse autoencoder, using the same <tt>sparseAutoencoderCost.m</tt> function from the previous assignments. (Use the frameworks from previous assignments to ensure that your code is working and vectorized.) The training step should take less than 25 minutes (on a reasonably fast computer). When it is completed, a visualization of pen strokes should be displayed.
Next, we will train the unlabeled dataset on the sparse autoencoder, using the same <tt>sparseAutoencoderCost.m</tt> function from the previous assignments. (Use the frameworks from previous assignments to ensure that your code is working and vectorized.) The training step should take less than 25 minutes (on a reasonably fast computer). When it is completed, a visualization of pen strokes should be displayed.
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The features learned by the sparse autoencoder should correspond to penstrokes.
The features learned by the sparse autoencoder should correspond to penstrokes.
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===Step Three: Extracting features===
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===Step 3: Extracting features===
After the sparse autoencoder is trained, we can use it to extract features from the handwritten digit images.  
After the sparse autoencoder is trained, we can use it to extract features from the handwritten digit images.  
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After doing so, this step will use your modified function to convert the raw image data to feature unit activations.  
After doing so, this step will use your modified function to convert the raw image data to feature unit activations.  
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===Step Four: Training and testing the logistic regression model===
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===Step 4: Training and testing the logistic regression model===
In this step, you should use your code from the softmax exercise (<tt>softmaxTrain.m</tt>) to train the softmax classifier using the training features (<tt>trainFeatures</tt>) and labels (<tt>trainLabels</tt>).
In this step, you should use your code from the softmax exercise (<tt>softmaxTrain.m</tt>) to train the softmax classifier using the training features (<tt>trainFeatures</tt>) and labels (<tt>trainLabels</tt>).
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===Step Five: Classifying on the test set===
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===Step 5: Classifying on the test set===
Finally, complete the code to make predictions on the test set (<tt>testFeatures</tt>) and see how your learned features perform! If you've done all the steps correctly, you should get an accuracy of about '''98%''' percent.
Finally, complete the code to make predictions on the test set (<tt>testFeatures</tt>) and see how your learned features perform! If you've done all the steps correctly, you should get an accuracy of about '''98%''' percent.
[[Category:Exercises]]
[[Category:Exercises]]

Revision as of 06:24, 8 May 2011

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