Mar 19, 2022 · 3 min read. ·. Mar 19, 2022. Non-negative Matrix Factorization or NMF is a method used to factorize a non-negative matrix, X, into the product of two lower rank matrices, A and B, such that AB ... In this paper, we propose SS-NMF: a semi-supervised non-negative matrix factorization framework for data clustering. In SS-NMF, users are able to provide supervision for clustering in terms of pairwise constraints on a few data objects specifying whether they "must" or "cannot" be clustered together. Nonnegative matrix factorization 3 each cluster/topic and models it as a weighted combination of keywords. Because of the nonnegativity constraints in NMF, the result of NMF can be viewed as doc-ument clustering and topic modeling results directly, which will be elaborated by theoretical and empirical evidences in this book chapter. Non-negative Matrix Factorization is applied with two different objective functions: the Frobenius norm, and the generalized Kullback-Leibler divergence. The latter is equivalent to Probabilistic Latent Semantic Indexing. The default parameters (n_samples / n_features / n_components) should make the example runnable in a couple of tens of seconds. Clustering-aware Graph Construction: ... Semi-Supervised Non-Negative Matrix Factorization with Dissimilarity and Similarity Regularization, Y. Jia, ... Clustering-aware Graph Construction: ... Semi-Supervised Non-Negative Matrix Factorization with Dissimilarity and Similarity Regularization, Y. Jia, ... A python program that applies a choice of nonnegative matrix factorization (NMF) algorithms to a dataset for clustering. clustering matrix-factorization least-squares topic-modeling nmf alternating-least-squares nonnegative-matrix-factorization active-set multiplicative-updates. Updated on Jun 10, 2019. Python. clustering and the Laplacian based spectral clustering. (2) We generalize this to bipartite graph clustering i.e., simultaneously clustering rows and columns of the rect-angular data matrix. The result is the standard NMF. (3) We extend NMFs to weighted NMF: W ≈ HSHT. (3) (4) We derive the algorithms for computing these fac-torizations. Oct 23, 2017 · Nonnegative matrix factorization and its graph regularized extensions have received significant attention in machine learning and data mining. However, existing approaches are sensitive to outliers and noise due to the utilization of the squared loss function in measuring the quality of graph regularization and data reconstruction. In this paper, we present a novel robust graph regularized NMF ... clustering and the Laplacian based spectral clustering. (2) We generalize this to bipartite graph clustering i.e., simultaneously clustering rows and columns of the rect-angular data matrix. The result is the standard NMF. (3) We extend NMFs to weighted NMF: W ≈ HSHT. (3) (4) We derive the algorithms for computing these fac-torizations. clustering and the Laplacian based spectral clustering. (2) We generalize this to bipartite graph clustering i.e., simultaneously clustering rows and columns of the rect-angular data matrix. The result is the standard NMF. (3) We extend NMFs to weighted NMF: W ≈ HSHT. (3) (4) We derive the algorithms for computing these fac-torizations. Nov 19, 2021 · Non-negative factorization (NNMF) does not return group labels for the entries in the original matrix. However, just like with principal component analysis (PCA), the clustering step can be performed afterwards using k-means or some other clustering technique. Hence NNMF might be a useful step, but itself is not a method for finding clusters in ... Jan 7, 2020 · Community detection is a critical issue in the field of complex networks. Capable of extracting inherent patterns and structures in high dimensional data, the non-negative matrix factorization (NMF) method has become one of the hottest research topics in community detection recently. However, this method has a significant drawback; most community detection methods using NMF require the number ... May 4, 2020 · To integrate this information, one often utilizes the non-negative matrix factorization (NMF) scheme which can reduce the data from different views into the subspace with the same dimension. Motivated by the clustering performance being affected by the distribution of the data in the learned subspace, a tri-factorization-based NMF model with an ... Nov 1, 2022 · An orthogonal deep non-negative matrix factorization (Deep-NMF) framework that aims to learn the non-linear parts-based representation for multi-view data is proposed. • The T-SNE visualizations of the features learned by the proposed Deep-NMF and its counterpart ascertain the effectiveness of the proposed framework for multi-view clustering. • Aug 6, 2018 · Non-negative matrix factorization with custom clustering: NMFk. NMF is a well-known unsupervised machine learning method created for parts-based representation 19,20 that has been successfully ... Jan 12, 2021 · Non-negative matrix factorization (NMF), as an efficient and intuitive dimension reduction algorithm, has been successfully applied to clustering tasks. However, there are still two dominating limitations. First, the original NMF only pays attention to the global data structure, ignoring the intrinsic geometry of the original higher-dimensional data. Second, the traditional pairwise distance ... 1. In non-negative matrix factorization (NMF), the problem is to minimize A − W H. Dimensions are A (m x n), W (m, k) and H (k, n). The matrix H reveals soft clustering assignments of n items over k clusters, and is called clustering indicator matrix. Values in H are constrained to have nonnegative numbers.Nov 20, 2020 · Non-negative Matrix factorization (NMF) , which maps the high dimensional text representation to a lower-dimensional representation, has become popular in text clustering due to its capability to learn part-based lower-order representation where groups can be identified accurately [1, 14]. Though the decomposed factor matrices are considerably ... Oct 23, 2017 · Nonnegative matrix factorization and its graph regularized extensions have received significant attention in machine learning and data mining. However, existing approaches are sensitive to outliers and noise due to the utilization of the squared loss function in measuring the quality of graph regularization and data reconstruction. In this paper, we present a novel robust graph regularized NMF ... Nov 1, 2022 · Non-negative matrix factorization (NMF) is one of the most favourable multi-view clustering methods due to its strong representation ability of non-negative data. However, NMF only factorizes the data matrix into two non-negative factor matrices, which may limit its ability to learn higher level and more complex hierarchical information. Aug 6, 2018 · Non-negative matrix factorization with custom clustering: NMFk. NMF is a well-known unsupervised machine learning method created for parts-based representation 19,20 that has been successfully ... Non-negative matrix factorization ( NMF or NNMF ), also non-negative matrix approximation [1] [2] is a group of algorithms in multivariate analysis and linear algebra where a matrix V is factorized into (usually) two matrices W and H, with the property that all three matrices have no negative elements. Apr 30, 2022 · Abstract. Non-negative matrix factorization (NMF) has attracted much attention for multi-view clustering due to its good theoretical and practical values. Although existing multi-view NMF methods have achieved satisfactory performance to some extent, there still exist the following problems: 1) most existing methods only consider the first ... to develop the joint non-negative matrix factorization framework for multi-view clustering. Let X = [X;1;:::;X;N] 2R M N + denote the nonnegative data matrix where each column represents a data point and each row represents one attribute. NMF aims to nd two non-negative matrix factors U = [Ui;k] 2RM K + and V = [Vj;k] 2R N K + whose Apr 1, 2022 · Sparse Nonnegative Matrix Factorization (SNMF) is a fundamental unsupervised representation learning technique, and it represents low-dimensional features of a data set and lends itself to a clustering interpretation. Nonnegative matrix factorization 3 each cluster/topic and models it as a weighted combination of keywords. Because of the nonnegativity constraints in NMF, the result of NMF can be viewed as doc-ument clustering and topic modeling results directly, which will be elaborated by theoretical and empirical evidences in this book chapter. Apr 16, 2013 · Background Non-negative matrix factorization (NMF) has been introduced as an important method for mining biological data. Though there currently exists packages implemented in R and other programming languages, they either provide only a few optimization algorithms or focus on a specific application field. There does not exist a complete NMF package for the bioinformatics community, and in ... Dec 18, 2013 · Abstract Nonnegative matrix factorization (NMF) provides a lower rank approximation of a nonnegative matrix, and has been successfully used as a clustering method. In this paper, we offer some conceptual understanding for the capabilities and shortcomings of NMF as a clustering method. Then, we propose Symmetric NMF (SymNMF) as a general framework for graph clustering, which inherits the ... Mar 19, 2022 · 3 min read. ·. Mar 19, 2022. Non-negative Matrix Factorization or NMF is a method used to factorize a non-negative matrix, X, into the product of two lower rank matrices, A and B, such that AB ... Nonnegative matrix factorization (NMF) provides a lower rank approximation of a nonnegative matrix, and has been successfully used as a clustering method. In this paper, we offer some conceptual understanding for the capabilities and shortcomings of NMF as a clustering method.Nov 1, 2021 · Abstract. Non-negative matrix factorization (NMF) is a dimension reduction method that extracts semantic features from high-dimensional data. Most of the developed optimization methods for NMF only pay attention to how each feature vector of factorized matrices should be modeled, and ignore the relationships among feature vectors. Clustering-aware Graph Construction: ... Semi-Supervised Non-Negative Matrix Factorization with Dissimilarity and Similarity Regularization, Y. Jia, ... By viewing K-means as a lower rank matrix factorization with special constraints rather than a clustering method, we come up with constraints to impose on NMF formulation so that it behaves as a variation of K-means. In K-means clustering, the objective function to be minimized is the sum of squared distances from each data point to its centroid. Jun 1, 2012 · As two popular matrix factorization techniques, concept factorization (CF) and non-negative matrix factorization (NMF) have achieved excellent results in multi-view clustering tasks. Compared with multi-view NMF, multi-view CF not only removes the non-negative constraint but also utilizes the idea of the kernel to learn the latent ... Sep 28, 2019 · Non-Negative Matrix Factorization Equation. Matrix Factorization form for clustering. Here, “X” is my data matrix which represents the data points in d-dimensions, where I have total “n ... Sep 29, 2020 · With the maturity of hyper-graph technology, Zeng et al. proposed Hyper-graph regularized Non-negative Matrix Factorization (HNMF) for image clustering . Furthermore, considering the manifold structure and the sparsity, Graph Regularized Robust Non-negative Matrix Factorization (GrRNMF) is proposed by Yu et al.. Apr 1, 2022 · Sparse Nonnegative Matrix Factorization (SNMF) is a fundamental unsupervised representation learning technique, and it represents low-dimensional features of a data set and lends itself to a clustering interpretation. Oct 23, 2017 · Nonnegative matrix factorization and its graph regularized extensions have received significant attention in machine learning and data mining. However, existing approaches are sensitive to outliers and noise due to the utilization of the squared loss function in measuring the quality of graph regularization and data reconstruction. In this paper, we present a novel robust graph regularized NMF ... Sep 30, 2021 · By decomposing original high dimensional non-negative data matrix X into two low dimensional non-negative factors U and V, namely basis matrix and coefficient matrix, such that X ≈ UVT. Moreover, the additive reconstruction with nonnegative constraints can lead to a parts-based representation for images [ 1 ], texts [ 2 ], and microarray data ... By viewing K-means as a lower rank matrix factorization with special constraints rather than a clustering method, we come up with constraints to impose on NMF formulation so that it behaves as a variation of K-means. In K-means clustering, the objective function to be minimized is the sum of squared distances from each data point to its centroid. Aug 20, 2006 · W. Xu, X. Liu, and Y. Gong. Document clustering based on non-negative matrix factorization. In SIGIR, pages 267--273, 2003. Google Scholar Digital Library; D. Zeimpekis and E. Gallopoulos. Clsi: A flexible approximation scheme from clustered term-document matrices. Proc. SIAM Data Mining Conf, pages 631--635, 2005. Google Scholar Cross Ref 1. In non-negative matrix factorization (NMF), the problem is to minimize A − W H. Dimensions are A (m x n), W (m, k) and H (k, n). The matrix H reveals soft clustering assignments of n items over k clusters, and is called clustering indicator matrix. Values in H are constrained to have nonnegative numbers.Nov 27, 2018 · Luong, K., Nayak, R. (2019). Clustering Multi-View Data Using Non-negative Matrix Factorization and Manifold Learning for Effective Understanding: A Survey Paper. In: P, D., Jurek-Loughrey, A. (eds) Linking and Mining Heterogeneous and Multi-view Data. Unsupervised and Semi-Supervised Learning. Mar 24, 2013 · Background: Non-negative matrix factorization (NMF) has been shown to be a powerful tool for clustering gene expression data, which are widely used to classify cancers. NMF aims to find two non-negative matrices whose product closely approximates the original matrix. 1. In non-negative matrix factorization (NMF), the problem is to minimize A − W H. Dimensions are A (m x n), W (m, k) and H (k, n). The matrix H reveals soft clustering assignments of n items over k clusters, and is called clustering indicator matrix. Values in H are constrained to have nonnegative numbers.May 4, 2020 · To integrate this information, one often utilizes the non-negative matrix factorization (NMF) scheme which can reduce the data from different views into the subspace with the same dimension. Motivated by the clustering performance being affected by the distribution of the data in the learned subspace, a tri-factorization-based NMF model with an ... Oct 23, 2017 · Nonnegative matrix factorization and its graph regularized extensions have received significant attention in machine learning and data mining. However, existing approaches are sensitive to outliers and noise due to the utilization of the squared loss function in measuring the quality of graph regularization and data reconstruction. In this paper, we present a novel robust graph regularized NMF ... Jul 19, 2021 · Abstract. Non-negative matrix factorization (NMF) is a powerful tool for data science researchers, and it has been successfully applied to data mining and machine learning community, due to its advantages such as simple form, good interpretability and less storage space. 1. In non-negative matrix factorization (NMF), the problem is to minimize A − W H. Dimensions are A (m x n), W (m, k) and H (k, n). The matrix H reveals soft clustering assignments of n items over k clusters, and is called clustering indicator matrix. Values in H are constrained to have nonnegative numbers.Aug 9, 2023 · Non-negative Matrix Factorization (NMF) is a data mining technique that splits data matrices by imposing restrictions on the elements' non-negativity into two matrices: one representing the data partitions and the other to represent the cluster prototypes of the data set. Aug 1, 2021 · Recently semi-supervised non-negative matrix factorization (NMF) has received a lot of attentions in computer vision, information retrieval and pattern recognition, because that partial label information can produce considerable improvement in learning accuracy of the algorithms. However, the existing semi-supervised NMF algorithms cannot make ... clustering and the Laplacian based spectral clustering. (2) We generalize this to bipartite graph clustering i.e., simultaneously clustering rows and columns of the rect-angular data matrix. The result is the standard NMF. (3) We extend NMFs to weighted NMF: W ≈ HSHT. (3) (4) We derive the algorithms for computing these fac-torizations. Non-negative Matrix Factorization (NMF) is a data mining technique that splits data matrices by imposing restrictions on the elements' non-negativity into two matrices: one representing the data partitions and the other to represent the cluster prototypes of the data set.Nov 27, 2018 · Luong, K., Nayak, R. (2019). Clustering Multi-View Data Using Non-negative Matrix Factorization and Manifold Learning for Effective Understanding: A Survey Paper. In: P, D., Jurek-Loughrey, A. (eds) Linking and Mining Heterogeneous and Multi-view Data. Unsupervised and Semi-Supervised Learning. Non-negative Matrix Factorization (NMF) is a data mining technique that splits data matrices by imposing restrictions on the elements' non-negativity into two matrices: one representing the data partitions and the other to represent the cluster prototypes of the data set.Non-negative factorization (NNMF) does not return group labels for the entries in the original matrix. However, just like with principal component analysis (PCA), the clustering step can be performed afterwards using k-means or some other clustering technique. Hence NNMF might be a useful step, but itself is not a method for finding clusters in ...In this post, we’ll cluster the scotches using non-negative matrix factorization (NMF). NMF approximately factors a matrix V into two matrices, W and H: If V in an n x m matrix, then NMF can be used to approximately factor V into an n x r matrix W and an r x m matrix H. Usually r is chosen to be much smaller than either m or n, for dimension ... Nov 1, 2021 · Abstract. Non-negative matrix factorization (NMF) is a dimension reduction method that extracts semantic features from high-dimensional data. Most of the developed optimization methods for NMF only pay attention to how each feature vector of factorized matrices should be modeled, and ignore the relationships among feature vectors. Nowadays, non-negative matrix factorization (NMF) based cluster analysis for multi-view data shows impressive behavior in machine learning. Usually, multi- Multi-view data clustering via non-negative matrix factorization with manifold regularization | SpringerLinkNov 13, 2018 · This is actually matrix factorization part of the algorithm. The Non-negative part refers to V, W, and H — all the values have to be equal or greater than zero, i.e., non-negative. Of course ... Mar 31, 2022 · Non-negative matrix factorization (NMF), which has widely used in multi-view clustering because it has straightforward interpretability for applications and can learn low-dimensional representation with more discriminative features [15,16,17]. It can decompose multi-view data of different dimensions into a subspace with the same dimension. Mar 10, 2021 · Matrix factorization, as a method of unsupervised learning, is another efficient method for cell clustering and is excellent in data dimension reduction or the extraction of latent factors. In particular, non-negative matrix factorization(NMF) (Lee & Seung, 1999) is a suitable method for dimension reduction to extract the features of gene ... Non-negative Matrix Factorization (NMF) is a data mining technique that splits data matrices by imposing restrictions on the elements' non-negativity into two matrices: one representing the data partitions and the other to represent the cluster prototypes of the data set.Jul 22, 2022 · matrix-factorization constrained-optimization data-analysis robust-optimization gradient-descent matlab-toolbox clustering-algorithm optimization-algorithms nmf online-learning stochastic-optimizers nonnegativity-constraints orthogonal divergence probabilistic-matrix-factorization nonnegative-matrix-factorization sparse-representations to develop the joint non-negative matrix factorization framework for multi-view clustering. Let X = [X;1;:::;X;N] 2R M N + denote the nonnegative data matrix where each column represents a data point and each row represents one attribute. NMF aims to nd two non-negative matrix factors U = [Ui;k] 2RM K + and V = [Vj;k] 2R N K + whose Aug 6, 2018 · Non-negative matrix factorization with custom clustering: NMFk. NMF is a well-known unsupervised machine learning method created for parts-based representation 19,20 that has been successfully ... Oct 22, 2019 · Background As one of the most popular data representation methods, non-negative matrix decomposition (NMF) has been widely concerned in the tasks of clustering and feature selection. However, most of the previously proposed NMF-based methods do not adequately explore the hidden geometrical structure in the data. At the same time, noise and outliers are inevitably present in the data. Results ... Oct 1, 2017 · A non-negative matrix factorization approach to extract heart sounds from mixtures composed of heart and lung sounds is addressed. Specifically, three contributions motivated by the clustering principle are presented in this work: two of these clusterings are based on spectral content and one is based on temporal content in order to ... Jun 1, 2012 · As two popular matrix factorization techniques, concept factorization (CF) and non-negative matrix factorization (NMF) have achieved excellent results in multi-view clustering tasks. Compared with multi-view NMF, multi-view CF not only removes the non-negative constraint but also utilizes the idea of the kernel to learn the latent ... May 4, 2020 · To integrate this information, one often utilizes the non-negative matrix factorization (NMF) scheme which can reduce the data from different views into the subspace with the same dimension. Motivated by the clustering performance being affected by the distribution of the data in the learned subspace, a tri-factorization-based NMF model with an ... Apr 16, 2013 · Background Non-negative matrix factorization (NMF) has been introduced as an important method for mining biological data. Though there currently exists packages implemented in R and other programming languages, they either provide only a few optimization algorithms or focus on a specific application field. There does not exist a complete NMF package for the bioinformatics community, and in ... 1. NMF (non-negative matrix factorization) based methods. NMF factorizes the non-negative data matrix into two non-negative matrices. 1.1 AAAI17 Multi-View Clustering via Deep Matrix Factorization (matlab) Deep Matrix Factorization is a variant of NMF. 1.2 ICPR16 Partial Multi-View Clustering Using Graph Regularized NMF (matlab) Nonnegative matrix factorization 3 each cluster/topic and models it as a weighted combination of keywords. Because of the nonnegativity constraints in NMF, the result of NMF can be viewed as doc-ument clustering and topic modeling results directly, which will be elaborated by theoretical and empirical evidences in this book chapter. Dec 1, 2020 · The general processing of non-negative matrix factorization for image clustering consists of two steps: (i) achieving the r-dimensional non-negative image representations, where the rank r is set to the expected number of clusters; (ii) adopting the traditional clustering techniques to accomplish the clustering task. Nevertheless, the previous ... Mar 5, 2022 · Non-negative matrix factorization (NMF) is an effective technique for clustering, which aims to find the product of two non-negative low-dimensional matrices that approximates the original matrix. Since the matrices must satisfy the non-negative constraints, the Karush–Kuhn–Tucker conditions need to be used to obtain the update rules for ... Dec 18, 2013 · Abstract Nonnegative matrix factorization (NMF) provides a lower rank approximation of a nonnegative matrix, and has been successfully used as a clustering method. In this paper, we offer some conceptual understanding for the capabilities and shortcomings of NMF as a clustering method. Then, we propose Symmetric NMF (SymNMF) as a general framework for graph clustering, which inherits the ... Dec 19, 2018 · 该文提出了一种新的矩阵分解思想――非负矩阵分解 (Non-negative Matrix Factorization，NMF)算法，即NMF是在矩阵中所有元素均为非负数约束条件之下的矩阵分解方法。. 该论文的发表迅速引起了各个领域中的科学研究人员的重视。. 优点：. 1. 处理大规模数据更快更便捷 ...
Jul 26, 2019 · As a classical data representation method, nonnegative matrix factorization (NMF) can well capture the global structure information of the observed data, and it has been successfully applied in many fields. It is generally known that the local manifold structures will have a better effect than the global structures in image recognition and clustering. The local structure information can well ... . Paris las vegas restaurants
Mar 1, 2021 · Graph-regularized non-negative matrix factorization (GNMF) is proved to be effective for the clustering of nonlinear separable data. Existing GNMF variants commonly improve model performance by adding different additional constraints or refining the model factorization form, which can lead to problems such as increased algorithm complexity or ... Apr 16, 2013 · Background Non-negative matrix factorization (NMF) has been introduced as an important method for mining biological data. Though there currently exists packages implemented in R and other programming languages, they either provide only a few optimization algorithms or focus on a specific application field. There does not exist a complete NMF package for the bioinformatics community, and in ... Aug 1, 2021 · Recently semi-supervised non-negative matrix factorization (NMF) has received a lot of attentions in computer vision, information retrieval and pattern recognition, because that partial label information can produce considerable improvement in learning accuracy of the algorithms. However, the existing semi-supervised NMF algorithms cannot make ... Apr 1, 2022 · Sparse Nonnegative Matrix Factorization (SNMF) is a fundamental unsupervised representation learning technique, and it represents low-dimensional features of a data set and lends itself to a clustering interpretation. Aug 9, 2023 · Non-negative Matrix Factorization (NMF) is a data mining technique that splits data matrices by imposing restrictions on the elements' non-negativity into two matrices: one representing the data partitions and the other to represent the cluster prototypes of the data set. In this post, we’ll cluster the scotches using non-negative matrix factorization (NMF). NMF approximately factors a matrix V into two matrices, W and H: If V in an n x m matrix, then NMF can be used to approximately factor V into an n x r matrix W and an r x m matrix H. Usually r is chosen to be much smaller than either m or n, for dimension ... Mar 21, 2021 · Nowadays, non-negative matrix factorization (NMF) based cluster analysis for multi-view data shows impressive behavior in machine learning. Usually, multi- Multi-view data clustering via non-negative matrix factorization with manifold regularization | SpringerLink Mar 10, 2021 · Matrix factorization, as a method of unsupervised learning, is another efficient method for cell clustering and is excellent in data dimension reduction or the extraction of latent factors. In particular, non-negative matrix factorization(NMF) (Lee & Seung, 1999) is a suitable method for dimension reduction to extract the features of gene ... Dec 19, 2018 · 该文提出了一种新的矩阵分解思想――非负矩阵分解 (Non-negative Matrix Factorization，NMF)算法，即NMF是在矩阵中所有元素均为非负数约束条件之下的矩阵分解方法。. 该论文的发表迅速引起了各个领域中的科学研究人员的重视。. 优点：. 1. 处理大规模数据更快更便捷 ... Non-negative Matrix Factorization (NMF) is a data mining technique that splits data matrices by imposing restrictions on the elements' non-negativity into two matrices: one representing the data partitions and the other to represent the cluster prototypes of the data set.Mar 21, 2021 · Nowadays, non-negative matrix factorization (NMF) based cluster analysis for multi-view data shows impressive behavior in machine learning. Usually, multi- Multi-view data clustering via non-negative matrix factorization with manifold regularization | SpringerLink Non-Negative Matrix Factorization (NMF). Find two non-negative matrices, i.e. matrices with all non-negative elements, (W, H) whose product approximates the non-negative matrix X. This factorization can be used for example for dimensionality reduction, source separation or topic extraction. The objective function is: 1. NMF (non-negative matrix factorization) based methods. NMF factorizes the non-negative data matrix into two non-negative matrices. 1.1 AAAI17 Multi-View Clustering via Deep Matrix Factorization (matlab) Deep Matrix Factorization is a variant of NMF. 1.2 ICPR16 Partial Multi-View Clustering Using Graph Regularized NMF (matlab) Nonnegative matrix factorization (NMF) provides a lower rank approximation of a nonnegative matrix, and has been successfully used as a clustering method. In this paper, we offer some conceptual understanding for the capabilities and shortcomings of NMF as a clustering method. .