It’s been a while since my last article on here and that’s because I have been busy preparing for my actuarial exam that is coming up in just two months. In the process of studying these past couple of weeks, I ran into a good old friend from way back in my first ever statistics class, linear regression.

As I started to learn more complex machine learning algorithms, I sometimes get caught up with building the fanciest model to solve a problem when in reality, a simple linear model could have easily gotten the job done. …

In this article, we will discuss k-means clustering, an unsupervised learning algorithm and learn how to implement it in R.

Introduction to unsupervised learning and k-means clustering

First of all, what is unsupervised learning?

In contrast to supervised learning where the label (output) of a predictive model is explicitly specified in advance, unsupervised learning allows the algorithm to identify the clusters within the data itself and subsequently label them accordingly.

K-means clustering is an example of an unsupervised learning algorithm and it works as follows:

1. Choose a number of clusters, K (this is what the k stands for in k-means clustering), into which the data are to…

Feature scaling is the process of normalising the range of features in a dataset.

Real-world datasets often contain features that are varying in degrees of magnitude, range and units. Therefore, in order for machine learning models to interpret these features on the same scale, we need to perform feature scaling.

In the world of science, we all know the importance of comparing apples to apples and yet many people, especially beginners, have a tendency to overlook feature scaling as part of their data preprocessing for machine learning. …

Missing values is one of the most common problems during data analysis and machine learning. Machine learning models require that a dataset does not contain any missing values before they can be fitted to the data. Therefore, it is crucial that we learn how to properly handle them.

I released a video tutorial a while back about handling missing data using Pandas and in that video, I spoke about the two main ways to deal with missing values in a dataset:

1. If there are only a few rows with missing values or if a column has an overwhelming number…

One of the most crucial preprocessing steps in any machine learning project is feature encoding. It is the process of turning categorical data in a dataset into numerical data. It is essential that we perform feature encoding because most machine learning models can only interpret numerical data and not data in text form.

In this article, we will learn:

• The difference between a nominal variable and an ordinal variable
• How OneHotEncoder and OrdinalEncoder can be used to encode these variables respectively
• Why the Scikit-learn library is preferred over the Pandas library when it comes to encoding categorical features

As usual…

Picture this. You’re excited to finally start on your first machine learning project, having spent the last couple of weeks completing an online machine learning course. You come up with a problem that you would like to solve using machine learning and one that you think you can properly put your new knowledge to the test. You happily jump onto Kaggle and found a dataset that you could work with. You open up Jupyter notebook, import and read the dataset.

All of a sudden, the initial confidence that you had disappears as you stare hopelessly at the hundreds of features…

I recently caught up with a data scientist working in the consulting industry and he was telling me about the grossly underrated part of his job that he wished he had known before starting his role and that is communication. Contrary to his initial belief that technical skills are all that is required to be a successful data scientist, he quickly realised that the ability to communicate is also equally if not more important.

In the real world, clients often do not have the luxury of time to go through the code has been written for a project line by…

If you know me, I am a big fan of Kaggle. God only knows how many times I have brought up Kaggle in my previous articles here on Medium.

But my journey on Kaggle wasn’t always filled with roses and sunshine, especially in the beginning. Due to my lack of experience, I was initially struggling to grasp the workflow behind a machine learning project as well as the different terminologies that were being used.

It was only after months of sifting through online resources which included many technical articles, documentation and tutorial videos that I slowly started to learn concepts…