Let’s understand some of the factors that can impact the final clusters that you obtain from the K-means algorithm. This would also give you an idea about the issues that you must keep in mind before you start to make clusters to solve your business problem. Thus, the major practical considerations involved in K-Means clustering […]
Practical Consideration in K Means Algorithm Read More »
Let’s go through the K-Means algorithm using a very simple example. Let’s consider a set of 10 points on a plane and try to group these points into, say, 2 clusters. So let’s see how the K-Means algorithm achieves this goal. [Note: If you don’t know what is meant by Euclidean distance, you’re advised to
Steps of the Algorithm Read More »
The next concept that is crucial for understanding how clustering generally works is the idea of centroids. If you remember your high school geometry, centroids are essentially the centre points of triangles. Similarly, in the case of clustering, centroids are the center points of the clusters that are being formed. Now before going to the
Euclidean Distance In the previous segments, you got an idea about how clustering works – it groups the objects on the basis of their similarity or closeness to each other. Now, the next important thing is to get into the nitty-gritty of how clustering algorithms generally work. You will learn about the 2 types of
K-Means clustering Read More »
Cost Function We can measure the accuracy of our hypothesis function by using a cost function. This takes an average difference (actually a fancier version of an average) of all the results of the hypothesis with inputs from x’s and the actual output y’s. J(theta_0, theta_1) = dfrac {1}{2m} displaystyle sum _{i=1}^m left ( hat{y}_{i}-
Model Representation To establish notation for future use, we’ll use x^{(i)}x(i) to denote the “input” variables (living area in this example), also called input features, and y^{(i)}y(i) to denote the “output” or target variable that we are trying to predict (price). A pair (x^{(i)} , y^{(i)} )(x(i),y(i)) is called a training example, and the dataset
Model and cost function Read More »
Unsupervised Learning Unsupervised learning allows us to approach problems with little or no idea what our results should look like. We can derive structure from data where we don’t necessarily know the effect of the variables. We can derive this structure by clustering the data based on relationships among the variables in the data. With
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Supervised Learning In supervised learning, we are given a data set and already know what our correct output should look like, having the idea that there is a relationship between the input and the output. Supervised learning problems are categorized into “regression” and “classification” problems. In a regression problem, we are trying to predict results
Supervised Learning Read More »
What is Machine Learning? What is Machine Learning? Two definitions of Machine Learning are offered. Arthur Samuel described it as: “the field of study that gives computers the ability to learn without being explicitly programmed.” This is an older, informal definition. Tom Mitchell provides a more modern definition: “A computer program is said to learn
