PPT-1 Clustering: K-Means

Machine Learning 10601 Fall 2014 Bhavana Dalvi Mishra PhD student LTI CMU Slides are based on materials from Prof  Eric Xing Prof   William Cohen and Prof Andrew Ng. Large-scale Single-pass k-Means . Clustering. Large-scale . k. -Means Clustering. Goals. Cluster very large data sets. Facilitate large nearest neighbor search. Allow very large number of clusters. Achieve good quality. Beth . Benas. Rizwan. . Habib. Alexander . Lowitt. Piyush. . Malve. Contents. What is Gene Clustering?. Two or more genes that code for the same or similar products. Two different processes for duplication of original genes via: . K. -means. David Kauchak. CS 451 – Fall 2013. Administrative. Final project. Presentations on Friday. 3 minute max. 1-2 PowerPoint slides. E-mail me by 9am on Friday. What problem you tackled and results. CSC 575. Intelligent Information Retrieval. Intelligent Information Retrieval. 2. Clustering Techniques and IR. Today. Clustering Problem and Applications. Clustering Methodologies and Techniques. Applications of Clustering in IR. Brendan and Yifang . April . 21 . 2015. Pre-knowledge. We define a set A, and we find the element that minimizes the error. We can think of as a sample of . Where is the point in C closest to X. . Margareta Ackerman. Work with . Shai. Ben-David, . Simina. . Branzei. , and David . Loker. . Clustering is one of the most widely used tools for exploratory data analysis.. . Social Sciences. Biology. Lecture outline. Distance/Similarity between data objects. Data objects as geometric data points. Clustering problems and algorithms . K-means. K-median. K-center. What is clustering?. A . grouping. of data objects such that the objects . issue in . computing a representative simplicial complex. . Mapper does . not place any conditions on the clustering . algorithm. Thus . any domain-specific clustering algorithm can . be used.. We . What is clustering?. Why would we want to cluster?. How would you determine clusters?. How can you do this efficiently?. K-means Clustering. Strengths. Simple iterative method. User provides “K”. Unsupervised . learning. Seeks to organize data . into . “reasonable” . groups. Often based . on some similarity (or distance) measure defined over data . elements. Quantitative characterization may include. Chapter 9 Finding Groups of Data – Clustering with k-means Objectives The ways clustering tasks differ from the classification tasks we examined previously How clustering defines a group, and how such groups are identified Produces a set of . nested clusters . organized as a hierarchical tree. Can be visualized as a . dendrogram. A . tree-like . diagram that records the sequences of merges or splits. Strengths of Hierarchical Clustering. clusters. CS771: Introduction to Machine Learning. Nisheeth. K. -means algorithm: . recap. 2. Notation: . or . is a . -dim one-hot vector. (. = 1 and . mean the same).  . K-means loss function: recap. Randomization tests. Cluster Validity . All clustering algorithms provided with a set of points output a clustering. How . to evaluate the “goodness” of the resulting clusters?. Tricky because .