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The problem of outliers is well-known in statistics: an outlier is a value that is far from the general distribution of the other observed values, and can often perturb the results of a statistical analysis. Various procedures exist for identifying outliers, in case they need to receive special...
Persistent link: https://www.econbiz.de/10011019703
The problem of outliers is well-known in statistics: an outlier is a value that is far from the general distribution of the other observed values, and can often perturb the results of a statistical analysis. Various procedures exist for identifying outliers, in case they need to receive special...
Persistent link: https://www.econbiz.de/10010849625
Correspondence analysis, when used to visualize relationships in a table of counts (for example, abundance data in ecology), has been frequently criticized as being too sensitive to objects (for example, species) that occur with very low frequency or in very few samples. In this statistical...
Persistent link: https://www.econbiz.de/10009323414
We construct a weighted Euclidean distance that approximates any distance or dissimilarity measure between individuals that is based on a rectangular cases-by-variables data matrix. In contrast to regular multidimensional scaling methods for dissimilarity data, the method leads to biplots of...
Persistent link: https://www.econbiz.de/10010849612
Correspondence analysis, when used to visualize relationships in a table of counts (for example, abundance data in ecology), has been frequently criticized as being too sensitive to objects (for example, species) that occur with very low frequency or in very few samples. In this statistical...
Persistent link: https://www.econbiz.de/10010851318
The book "Mathematics and Archaeology", consisting of 25 chapters by a range of international scholars in archaeology, will be published by Chapman & Hall in 2014. The present document, written as an invited Epilogue to the book, recounts the rediscovery of the book 275 years later by an...
Persistent link: https://www.econbiz.de/10010891944
Most methods of multivariate analysis rely on a measure of proximity between individual cases or samples to quantify inter-sample differences. The choice of this measure is fundamental to the method and its subsequent results. For example, when data are abundance counts of a set of species at...
Persistent link: https://www.econbiz.de/10010933544
We construct a weighted Euclidean distance that approximates any distance or dissimilarity measure between individuals that is based on a rectangular cases-by-variables data matrix. In contrast to regular multidimensional scaling methods for dissimilarity data, the method leads to biplots of...
Persistent link: https://www.econbiz.de/10010682977
The application of correspondence analysis to square asymmetric tables is often unsuccessful because of the strong role played by the diagonal entries of the matrix, obscuring the data off the diagonal. A simple modification of the centering of the matrix, coupled with the corresponding change...
Persistent link: https://www.econbiz.de/10005772235
Hierarchical clustering is a popular method for finding structure in multivariate data, resulting in a binary tree constructed on the particular objects of the study, usually sampling units. The user faces the decision where to cut the binary tree in order to determine the number of clusters to...
Persistent link: https://www.econbiz.de/10009002566