Category Archives: Machine Learning

Calling a Function Many Times that Generates Random Numbers and the Role of Experience in Programming

Posted on May 6, 2019 by jamesdmccaffrey

There are two main advantages of experience for computer programmers. First, an experienced programmer has a mental catalog of many techniques and doesn’t have to do much research and so he is much faster than an inexperienced programmer. Second, an … Continue reading →

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Weighted k-NN Classification Using C#

Posted on May 2, 2019 by jamesdmccaffrey

I wrote an article titled “Weighted k-NN Classification Using C#” in the May 2019 issue of Microsoft MSDN Magazine. See https://msdn.microsoft.com/en-us/magazine/mt833446. The k-NN (k-nearest neighbors) algorithm is very simple but there are several tricky implementation details. In the article I … Continue reading →

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Computing the Inverse of Matrix

Posted on April 30, 2019 by jamesdmccaffrey

The inverse of a matrix is used in many, many machine learning algorithms. In ordinary mathematics, the inverse of a number n is a number ni so that n * ni = 1. For example, if n = 5 the … Continue reading →

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Investigating Neural Network Dropout Using JavaScript

Posted on April 29, 2019 by jamesdmccaffrey

I have implemented quite a few different types of neural networks using several different programming languages. The other day I took a close look at implementing a neural network with dropout training, using JavaScript. Dropout is a technique that is … Continue reading →

Posted in JavaScript, Machine Learning | 4 Comments

The Difference Between Linearly Separable Data and a Linear Classifier in Machine Learning

Posted on April 27, 2019 by jamesdmccaffrey

The terms “linearly separable data” and “linear classifier” often appear in the context of machine learning. The terms sound a lot alike but aren’t closely related in the context of ML, even though the terms are closely related in the … Continue reading →

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Weighted k-NN Classification Using Python

Posted on April 22, 2019 by jamesdmccaffrey

I wrote an article titled, “Weighted k-NN Classification Using Python” in the April 2019 issue of Visual Studio Magazine. See https://visualstudiomagazine.com/articles/2019/04/01/weighted-k-nn-classification.aspx. The weighted k-nearest neighbors (k-NN) classification algorithm is a relatively simple technique to predict the class of an item … Continue reading →

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Neural Network Momentum using JavaScript

Posted on April 19, 2019 by jamesdmccaffrey

I’ve been slowly but surely implementing core neural network functionality using the JavaScript language. My most recent exploration was modifying a back-propagation function so that it used momentum. The motivation is to speed up training. The idea is best explained … Continue reading →

Posted in JavaScript, Machine Learning | 2 Comments

I Give a Talk on Binary Classification Using Keras

Posted on April 17, 2019 by jamesdmccaffrey

I recently gave a short workshop/talk at the tech company I work for on binary classification using the Keras neural network code library. The goal of a binary classification problem is to predict something that can take on one of … Continue reading →

Posted in Keras, Machine Learning | 1 Comment

The Difference Between Cross Entropy and Binary Cross Entropy

Posted on April 15, 2019 by jamesdmccaffrey

The basic ideas of cross entropy error and binary cross entropy error are relatively simple. But they’re often a source of confusion for developers who are new to machine learning because of the many topics related to how the two … Continue reading →

Posted in Machine Learning | 2 Comments

Applying a Permutation to an Array

Posted on April 14, 2019 by jamesdmccaffrey

A permutation of order n is an arrangement of the numbers 0 through n-1. For example, one permutation of order 5 is (4, 2, 0, 1, 3). Suppose you have an array of (“C”, “E”, “A”, “B”, “D”) and the … Continue reading →

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