Category Archives: R Language

R Language S4 OOP Object Initialization

Posted on November 20, 2016 by jamesdmccaffrey

I have a love-hate-love relationship with the R language. I like the huge R set of libraries (packages). But. R language syntax is very different from other languages so there’s a huge time cost to switch context from any language … Continue reading →

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Logistic Regression using Newton-Raphson

Posted on November 18, 2016 by jamesdmccaffrey

Logistic regression (LR) is a machine learning technique that makes predictions in situations where the outcome can be one of two possible values. For example, you might want to predict if a person died or not (Y), based on Age, … Continue reading →

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R Language Miscellaneous Matrix Techniques

Posted on November 16, 2016 by jamesdmccaffrey

The R language has a built-in kmeans() function for k-means data clustering. I was thinking about coding an R language custom k-means function from scratch. In most languages — C#, JavaScript, Python, etc. — I’d just start coding because I … Continue reading →

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Neural Networks using the R nnet Package

Posted on November 12, 2016 by jamesdmccaffrey

I wrote an article titled “Neural Networks using the R nnet Package” in the November 2016 issue of Visual Studio Magazine. See https://visualstudiomagazine.com/Articles/2016/11/01/Using-the-R-nnet-Package.aspx. A neural network is a software system that can use data to make predictions. For example, a … Continue reading →

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Support Vector Machines (SVM) using the R Language

Posted on November 10, 2016 by jamesdmccaffrey

A Support Vector Machine (SVM) is a machine learning algorithm that can do classification. SVMs were all the rage a few years ago but they’ve fallen out of favor a bit recently (deep neural networks are the current craze). In … Continue reading →

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Neural Networks from Scratch using R

Posted on October 23, 2016 by jamesdmccaffrey

Just for fun I decided to code up a basic neural network from scratch using the R language. I did so using the R6 OOP model. My three observations/conclusions are: 1. Because R is interpreted, R is too slow for … Continue reading →

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The Sign Test using R

Posted on October 6, 2016 by jamesdmccaffrey

I wrote an article in the October 2016 issue of Visual Studio Magazine titled “Results Are in – the Sign Test using R”. See https://visualstudiomagazine.com/articles/2016/10/01/sign-test-using-r.aspx. The Sign Test is used to analyze “before-and-after” data to determine if there’s been an … Continue reading →

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R Language Searching and Sorting

Posted on September 12, 2016 by jamesdmccaffrey

I wrote an article titled “R Language Searching and Sorting” in the September 2016 issue of Visual Studio Magazine. See https://visualstudiomagazine.com/articles/2016/09/01/r-language-searching-and-sorting.aspx. In a nutshell, R has a built-in sort function that can sort the values in a vector using a … Continue reading →

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Logistic Regression using R – Briefly

Posted on August 31, 2016 by jamesdmccaffrey

Logistic regression is a technique used to make a prediction when the thing to predict can take only one of two values. For example, suppose you want to predict a person’s political party (“red” or “blue”) based on their age … Continue reading →

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Two-Color Scatter Plots using the R plot() Function

Posted on August 30, 2016 by jamesdmccaffrey

I usually use Excel to create my graphs but sometimes I’ll use R, especially when I’m using R anyway for some sort of data analysis. So this morning I wanted to make a simple scatter plot based on this data … Continue reading →

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