Machine Learning

Important Terms in Hierarchical Clustering Linkage Methods Suppose there are (a) original observations a[0],…,a[|a|−1] in cluster (a) and (b) original objects b[0],…,b[|b|−1] in cluster (b), then in order to combine these clusters we need to calculate the distance between two clusters (a) and (b). Say a point (d) exists thatContinue Reading

We usually start with K-Means clustering. After going through several tutorials and Medium stories you will be able to implement k-means clustering easily. But as you implement it, a question starts to bug your mind: how can we measure its goodness of fit? Supervised algorithms have lots of metrics to checkContinue Reading

A fundamental step for any unsupervised algorithm is to determine the optimal number of clusters into which the data may be clustered. The Elbow Method is one of the most popular methods to determine this optimal value of k.We now demonstrate the given method using the K-Means clustering technique using the Sklearn library ofContinue Reading

Introduction to Hierarchical Clustering Hierarchical clustering is another unsupervised learning algorithm that is used to group together the unlabeled data points having similar characteristics. Hierarchical clustering algorithms falls into following two categories − Agglomerative hierarchical algorithms − In agglomerative hierarchical algorithms, each data point is treated as a single cluster andContinue Reading

Introduction to Mean-Shift Algorithm As discussed earlier, it is another powerful clustering algorithm used in unsupervised learning. Unlike K-means clustering, it does not make any assumptions; hence it is a non-parametric algorithm. Mean-shift algorithm basically assigns the datapoints to the clusters iteratively by shifting points towards the highest density ofContinue Reading

Introduction to K-Means Algorithm K-means clustering algorithm computes the centroids and iterates until we it finds optimal centroid. It assumes that the number of clusters are already known. It is also called flat clustering algorithm. The number of clusters identified from data by algorithm is represented by ‘K’ in K-means. In thisContinue Reading

Clustering or cluster analysis is a machine learning technique, which groups the unlabelled dataset. It can be defined as “A way of grouping the data points into different clusters, consisting of similar data points. The objects with the possible similarities remain in a group that has less or no similarities withContinue Reading

What Are Hyperparameters? When a model is being trained on a data set, it determines the best parameters for each predictor variable. This can be seen in a linear regression, where the coefficients are determined for each variable used in the model. The coefficients in this case are the parameters:Continue Reading

Cross-validation is a technique for validating the model efficiency by training it on the subset of input data and testing on previously unseen subset of the input data. We can also say that it is a technique to check how a statistical model generalizes to an independent dataset. In machine learning, thereContinue Reading