Tag Archives | machine learning

Stochastic Gradient Descent (SGD) with Python

In last week’s blog post, we discussed gradient descent, a first-order optimization algorithm that can be used to learn a set of classifier coefficients for parameterized learning. However, the “vanilla” implementation of gradient descent can be prohibitively slow to run on large datasets — in fact, it can even be considered computationally wasteful. Instead, we should apply Stochastic […]

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Understanding regularization for image classification and machine learning

In previous tutorials, I’ve discussed two important loss functions: Multi-class SVM loss and cross-entropy loss (which we usually refer to in conjunction with Softmax classifiers). In order to to keep our discussions of these loss functions straightforward, I purposely left out an important component: regularization. While our loss function allows us to determine how well (or poorly) our […]

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Softmax Classifiers Explained

Last week, we discussed Multi-class SVM loss; specifically, the hinge loss and squared hinge loss functions. A loss function, in the context of Machine Learning and Deep Learning, allows us to quantify how “good” or “bad” a given classification function (also called a “scoring function”) is at correctly classifying data points in our dataset. However, […]

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Multi-class SVM Loss

A couple weeks ago,we discussed the concepts of both linear classification and parameterized learning. This type of learning allows us to take a set of input data and class labels, and actually learn a function that maps the input to the output predictions, simply by defining a set of parameters and optimizing over them. Our linear classification tutorial focused […]

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How to tune hyperparameters with Python and scikit-learn

In last week’s post, I introduced the k-NN machine learning algorithm which we then applied to the task of image classification. Using the k-NN algorithm, we obtained 57.58% classification accuracy on the Kaggle Dogs vs. Cats dataset challenge: The question is: “Can we do better?” Of course we can! Obtaining higher accuracy for nearly any machine learning algorithm […]

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