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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
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
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
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
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 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
This study shows how correspondence analysis may be applied to a subset of response categories from a questionnaire survey (e.g., the subset of undecided responses or the subset of responses for a particular category across several questions). The idea is to maintain the original relative...
Persistent link: https://www.econbiz.de/10011136779
Canonical correspondence analysis and redundancy analysis are two methods of constrained ordination regularly used in the analysis of ecological data when several response variables (for example, species abundances) are related linearly to several explanatory variables (for example,...
Persistent link: https://www.econbiz.de/10010849617
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